제가 지금 Breakout이라고 벽돌깨기 게임을 만드는 과제를 하고 있는데 기본적인 요구사항은 다 충족시켜서 만들어 놨거든요

근데 게임 시작 전, 스타트 버튼을 누르면 게임 화면으로 전환되어서 게임이 시작될 수 있게끔 하고 싶은 욕심이 생겨서 그걸 구현해보려고 하다가 지금 막혀버린 상태입니다ㅠㅠ

클래스를 따로 만들어서 1번째 클래스가 게임 로비화면 이고 2번째 클래스가 게임 실행 화면 입니다. 이 둘을 어떻게 연결해줘야 할지 정말 막막합니다... 아직 자바 한 달 째라 뭐가 뭔지도 모르겠고... 도와주신다면 정말 감사하겠습니다. 밑에 코드 첨부합니다.

import java.awt.Dimension;
import javax.swing.*;
import java.awt.event.*;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.SwingConstants;

public class Main extends JFrame{

    public static void main(String[] args) {
        Breakout breakout = new Breakout();

        JFrame frame = new JFrame();
        frame.setVisible(true);
        frame.setSize(Breakout.APPLICATION_WIDTH, Breakout.APPLICATION_HEIGHT);
        frame.setTitle("게임 로비");
         // 프레임을 닫았을 때 프로그램이 종료되도록 설정
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);


        frame.setLayout( null );


        //JLabel gameTitle = new JLabel("BREAK OUT");
        //gameTitle.setLocation((frame.getWidth()-gameTitle.getWidth())/2, 100);
//        gameTitle.setBounds(150, 100, 100, 50);
//        gameTitle.setHorizontalAlignment(JLabel.CENTER);
//      frame.add(gameTitle);

        JButton startButton = new JButton("Game Start");
        //JButton exitButton = new JButton("Exit");


        startButton.setBounds(frame.getWidth()/2 - 100, frame.getHeight()/2 - 150, 200, 100);
        //exitButton.setBounds(frame.getWidth()/2 - 100, frame.getHeight()/2 - 50, 200, 100);

        frame.add(startButton);
        //frame.add(exitButton);

        startButton.addActionListener( new ActionListener(){

                    public void actionPerformed(ActionEvent e) {

                        System.out.println("버튼이 클릭되었습니다."); 
                        frame.setVisible(false);
                        breakout.start();
                        breakout.run();
                    }



        });

}
}

/*
 * File: Breakout.java
 * -------------------
 * This file will eventually implement the game of Breakout.
 */

import java.applet.AudioClip;
import java.awt.Color;
import java.awt.event.MouseEvent;
import java.io.File;

import javax.sound.sampled.AudioInputStream;
import javax.sound.sampled.AudioSystem;
import javax.sound.sampled.Clip;
import javax.sound.sampled.LineUnavailableException;
import javax.swing.JFrame;

import acm.graphics.GLabel;
import acm.graphics.GObject;
import acm.graphics.GOval;
import acm.graphics.GRect;
import acm.program.GraphicsProgram;
import acm.util.MediaTools;
import acm.util.RandomGenerator;

public class Breakout extends GraphicsProgram {

/** Width and height of application window in pixels */
    public static final int APPLICATION_WIDTH = 400;
    public static final int APPLICATION_HEIGHT = 600;

/** Dimensions of game board (usually the same) */
    private static final int WIDTH = APPLICATION_WIDTH;
    private static final int HEIGHT = APPLICATION_HEIGHT;

/** Dimensions of the paddle */
    private static final int PADDLE_WIDTH = 60;
    private static final int PADDLE_HEIGHT = 10;

/** Offset of the paddle up from the bottom */
    private static final int PADDLE_Y_OFFSET = 30;

/** Number of bricks per row */
    private static final int NBRICKS_PER_ROW = 10;

/** Number of rows of bricks */
    private static final int NBRICK_ROWS = 10;

/** Separation between bricks */
    private static final int BRICK_SEP = 4;

/** Width of a brick */
    private static final int BRICK_WIDTH =
      (WIDTH - (NBRICKS_PER_ROW - 1) * BRICK_SEP) / NBRICKS_PER_ROW;

/** Height of a brick */
    private static final int BRICK_HEIGHT = 8;

/** Radius of the ball in pixels */
    private static final int BALL_RADIUS = 10;

/** Offset of the top brick row from the top */
    private static final int BRICK_Y_OFFSET = 70;

/** Number of turns */
    private static final int NTURNS = 3;

/** 볼이 떨어질 때의 Pause */
    private static final int Pause = 5;

/*  변수 생성부  */
    Color color[] = {Color.RED, Color.ORANGE, Color.YELLOW, Color.GREEN, Color.CYAN};
    public GRect brick, paddle; 
    public GOval ball; 
    public GLabel youWin, youLose, turn, scoreLabel;
    private double vx, vy;
    private RandomGenerator rgen = new RandomGenerator();
    public GObject collider;
    int brickCount = NBRICKS_PER_ROW * NBRICK_ROWS;
    int nTurns = NTURNS; int score = 0;
    AudioClip bounceClip = MediaTools.loadAudioClip("bounce.au");
    File file, file2; AudioInputStream inGame, fail;Clip clip, clip2;
    boolean leftTop, leftBottom, rightTop, rightBottom;
    JFrame frame;

/* Method: run() */
/** Runs the Breakout program. */
    public void run() {
        playMusic();
        while(true) {
            play();
            if(nTurns ==0 || brickCount == 0) {
                break;
            }

    }


    }
    public void init(){
        this.removeAll();
        drawObjects();
        addMouseListeners();
        drawScoreLabel();
        drawBall();
        brickCount = NBRICKS_PER_ROW * NBRICK_ROWS;
    }

    public void play() {
        bounceBall(); moveBall();
        pause(Pause); getCollidingObject();
        removeBrick();remove(scoreLabel);drawScoreLabel();
        WinLose();
    }

    public void playMusic() {
         file = new File("/Users/jeong-gahyeon/Downloads/ingame.au");
         file2 = new File("/Users/jeong-gahyeon/Downloads/fail.au");
         System.out.println(file2.exists());
         try {  
                inGame = AudioSystem.getAudioInputStream(file);
                clip = AudioSystem.getClip();
                clip.open(inGame); clip.start();     
            } catch(Exception e) {
                e.printStackTrace();
            }
    }

    public void drawBrick(double x, double y, int c) {
        brick = new GRect(x, y, BRICK_WIDTH, BRICK_HEIGHT);
        brick.setFilled(true);
        brick.setFillColor(color[c]);
        add(brick);
    }   

    public void drawObjects() {     
        paddle = new GRect(PADDLE_WIDTH,PADDLE_HEIGHT);
        paddle.setFilled(true);

        turn = new GLabel("Turn : " + nTurns);
        add(turn, 0, HEIGHT - 100);

        int c = 0;
        for(int j = 0; j < NBRICK_ROWS; j++) {
            double brick_startY = (BRICK_HEIGHT + BRICK_SEP) * (j+1);
                if(j == 0) {
                    c = 0;
                }else if (j % 2 == 0) {
                    c += 1;
                }           
            for(int i = 0; i < NBRICKS_PER_ROW; i++) {
                double brick_startX = 1.5 + (BRICK_WIDTH + BRICK_SEP) * i;  
                drawBrick(brick_startX, brick_startY, c);
            }
        }
    }

    public void drawScoreLabel() {
        scoreLabel = new GLabel("Score : " + score);
        add(scoreLabel, 0, turn.getY() - turn.getAscent() * 2); 
    }

    /** MouseEvent : 마우스 포인터 움직임에 따라 paddle이 움직이게끔 함 */
    // 만약 paddle이 벽 밖 (화면 사이즈 밖)으로 나가려고 하면,paddle의 좌표를 다시 조정해줌으로써 넘어가지 않도록 함
    public void mouseMoved(MouseEvent e) {
        double paddleX= e.getX()-PADDLE_WIDTH/2;
        if (paddleX>(WIDTH - PADDLE_WIDTH)) {
            paddleX=(WIDTH - PADDLE_WIDTH);
        }else if (paddleX<0) {
            paddleX=0;
        }
        add(paddle,paddleX,HEIGHT - PADDLE_Y_OFFSET*2);
    }

    public void drawBall() {
        waitForClick();
        vx = rgen.nextDouble(1.0, 3.0); 
        if (rgen.nextBoolean(0.5)) vx = -vx; 
        vy = 3.0;
        //랜덤의 x좌표에서 공이 아래로 떨어지게끔 함.
        double x = rgen.nextDouble(0, (double)WIDTH);

        ball = new GOval(x,HEIGHT/2,BALL_RADIUS,BALL_RADIUS);
        ball.setFilled(true);
        add(ball);

    }

    public void moveBall() {
        ball.move(vx, vy);
    }

    public void bounceBall() {
        if(ball.getY() - BALL_RADIUS <= 0 ) {
            vy = -vy;
            bounceClip.play();
        }
        //if(ball.getY() + BALL_RADIUS >= HEIGHT) vy = -vy;
        if(ball.getX()+BALL_RADIUS >= WIDTH) {
            vx = -vx;
            bounceClip.play();
        }
        if(ball.getX()-BALL_RADIUS <= 0) {
            vx = -vx;
            bounceClip.play();
        }

        if(getCollidingObject() == paddle) {
            //빠르게 움직이면 glued 되는 현상을 해결하기 위함.
            vy = -1 * Math.abs(vy);
            bounceClip.play();
        }else if (getCollidingObject() == brick) {
            removeBrick();
        }
    }

    public GObject getCollidingObject() {
        leftTop = false; rightTop = false; leftBottom = false; rightBottom = false;
        if (getElementAt(ball.getX(), ball.getY()) != null) {
            collider = getElementAt(ball.getX(), ball.getY());
            leftTop = true;
        }else if(getElementAt(ball.getX()+ 2 * BALL_RADIUS, ball.getY()) != null){
            collider = getElementAt(ball.getX()+ 2 * BALL_RADIUS, ball.getY());
            rightTop = true;
        }else if(getElementAt(ball.getX(), ball.getY() + 2 * BALL_RADIUS) != null){
            collider = getElementAt(ball.getX(), ball.getY()+ 2 * BALL_RADIUS);
            leftBottom = true;
        }else if(getElementAt(ball.getX()+ 2 * BALL_RADIUS, ball.getY() + 2 * BALL_RADIUS) != null){
            collider = getElementAt(ball.getX()+ 2 * BALL_RADIUS, ball.getY() + 2 * BALL_RADIUS);
            rightBottom = true;
        }else {
            collider = null;
        }

        return collider;
    }

    public void removeBrick() {
        if (getCollidingObject() != null && getCollidingObject() != paddle && getCollidingObject() != turn && getCollidingObject() != scoreLabel) {
            remove(getCollidingObject());
            vy = -vy;
            bounceClip.play();
            brickCount--;
            score += 5;
            System.out.println(brickCount + " " + score);

        }
    }

    public void WinLose() {
        youWin = new GLabel("You Win!");
        youLose = new GLabel("You Lose!");
        GLabel finScore = new GLabel("Your Final Score : " + score);

        if(brickCount == 0) {
            removeAll();
            add(youWin, (WIDTH - youWin.getWidth())/2, HEIGHT/2);
            add(finScore,(WIDTH - finScore.getWidth())/2, youWin.getY() + youWin.getAscent()*2);

        }else if(ball.getY() + BALL_RADIUS*2 >= HEIGHT) {
            nTurns--;
            if(nTurns > 0) {
            pause(30);
            this.init();

            }else if (nTurns == 0) {
                removeAll();
                clip.stop();
                try {                       
                    fail = AudioSystem.getAudioInputStream(file2);              
                    clip2 = AudioSystem.getClip();                      
                    clip2.open(fail); clip2.start();                        
                 } catch(Exception e) {
                     e.printStackTrace();
                    }

                add(youLose,(WIDTH - youLose.getWidth())/2, HEIGHT/2 - youLose.getAscent());
                add(finScore,(WIDTH - finScore.getWidth())/2, youLose.getY() + youLose.getAscent()*2);
            }
        }   
    }

    public void mouseClicked(MouseEvent e) {
        if(nTurns == 0) {
            removeAll();
            playMusic();
            brickCount = 100; nTurns = NTURNS;
            while(true) {
                play();
                if(nTurns ==0 || brickCount == 0) {
                    break;
                }
        }
    }





}
}