Need help on Multiple Moving Shapes

[Majeh]

As the title says I need some help trying to figure out how to make multiple shapes that move independently of each other. I managed to make a program that can make one shape move around after spending an hour or two looking up how to use the Thread.sleep() and repaint(). Anyway here's what I got.

import java.awt.Graphics;
import javax.swing.JPanel;
import java.awt.*;
import java.util.Random;

public class Shapes extends JPanel implements Runnable
{

    Random myR = new Random();
    int x_pos;
    int y_pos;
    int x_width;
    int y_height;
    int right=5;
    int left= -5;
    int up=-5;
    int down = 5;
    int width, height;
    boolean goDown, goRight;

    public Shapes(int x, int y, int xw, int yh)
    {
         x_pos = x;
         y_pos = y;
         x_width = xw;
         y_height = yh;
    }

    public void init()
    {

    }

    public void start ()
    {

        Thread th = new Thread (this);
        th.start ();
    }

    @Override
    public void paintComponent( Graphics g )
    {
        super.paintComponent( g );

        g.setColor(Color.BLUE);
        g.fillRect(0, 0, getWidth(), getHeight());
        g.setColor(new Color(myR.nextInt(255), myR.nextInt(255), myR.nextInt(255)));
        g.fillOval(x_pos, y_pos, x_width, y_height);

    }

    public void drawShape (int nx, int ny)
    {
        x_pos= nx;
        y_pos= ny;
        repaint();
    }

    public void run ()
    {

        goRight = true;
        goDown = true;

        while (true)
        {

            moveShape();
            drawShape(x_pos, y_pos);
            repaint();

            try
            {
                Thread.sleep (25);
            }
            catch (InterruptedException ex)
            {
                    // do nothing
            }

        }
        
    }

    public void moveShape()
    {

        if(goRight)
        {
            x_pos += right;
            if (x_pos >= (getWidth() - x_width))
                goRight = false;
        }
        else
        {
            x_pos += left;
            if ( x_pos <= 0)
                goRight =  true;
        }
        if(goDown)
        {
            y_pos += down;
            if(y_pos >= getHeight()-y_height)
                goDown = false;
        }
        else
        {
            y_pos += up;
            if(y_pos <= 0)
                goDown = true;
        }

    }
    
}

Any suggestions on how I would go about this with what I got so far?

[Majeh]

Any suggestions?