New to Java

I am working on a project for aircraft seating and what i have to do is create square on the screen as seat. I got to draw 180 squares on the screen and it sounds easy but i have been stuck at it for about 10 days now my superviser doesn't know java so he can't help me on what i should do next and java superviser's told me they have no time to see me so if anyone here can help to guide me where i am goin wrong or how i should do it would be very helpful. Here is the code i have so far i think i am maybe close to gettin it working but then again i could be far off.

import java.awt.BorderLayout;
import java.awt.Graphics;
import java.awt.Dimension;
import java.awt.GridLayout;
import javax.swing.JFrame;
import javax.swing.JPanel;

public class Seating extends JFrame {

    private JPanel boardPanel;
    private JPanel panel2;
    private Square board[][];
   
    public Seating() {

        boardPanel = new JPanel();
        boardPanel.setLayout(new GridLayout(6,30,0,0));

        //create board
        board = new Square[6][30]; 

        //rows in the board
       for(int row = 0; row < board.length; row++)
       {
           //column on the board
            for(int column = 0; column < board[row].length; column++)
            {
                //create square
                board[row][column] = new Square(' ', 3 * row + column);
                //add square
                boardPanel.add(board[row][column]);
            }
       }

            panel2 = new JPanel();
            panel2.add(boardPanel, BorderLayout.CENTER);
            add(panel2, BorderLayout.CENTER);

            setSize(2000,1500);
            setVisible(true);
    }

             private class Square extends JPanel
            {

                public Dimension getPreferedSize()
                {
                  return new Dimension(20,20);
                }

                public Dimension getMinimumSize()
                {
                    return getPreferedSize();
                }

                public void paintComponent(Graphics g)
                {
                    super.paintComponents(g);

                    g.drawRect(0, 0, 19, 19);

                }
            }
}