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JTabbedPane Malfunctioning

I have a problem with my code. I am trying to get into user interfaces in Java, and have started using JOptionPane. At the moment, I'm experimenting with JTabbedPane, but I have a problem with it. My problem is the following: when I try to run the code, so that a panel with one tab appears reading 'You are using the program "CarDealership".', nothing happens. I don't know what's the problem, but my terminal reads the following when I compile and run my program...:
Terminal...: TerminalOutput
My code...: ProgramCode
I'm coding in Visual Studio Code, and, as you can tell by reviewing the code, I am from México. I translated the variables used in the program in a comment. Thank you for reading!
Code in text...:
/*
The name of the program translates to 'ProgCarDealership'.
Variables used...:
Example: 'Type/NameInSpanish/NameInEnglish'
- JTabbedPane/Pestañas/Tabs
- JLabel/Contenido/Content
- JPanel/Pestaña1/Tab1
*/
import javax.swing.*;
public class ProgLoteDeCarros extends JFrame
{
public VentanaPrincipal()
{
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setExtendedState(MAXIMIZED_BOTH);
setVisible(true);
setTitle("Programa Lote de Carros");
JTabbedPane Pestañas = new JTabbedPane();
JPanel Pestaña1 = new JPanel();
JLabel Contenido = new JLabel ("Estas usando el programa 'Lote de Carros'.");
Pestaña1.add(Contenido);
Pestañas.addTab("Información", Pestaña1);
getContentPane().add(Pestañas);
}
public static void main (String [] Yoshi)
{
ProgLoteDeCarros VentanaPrincipal = new ProgLoteDeCarros();
}

Need Help Updating JTextArea - Java

I'm on week three of a Java class. I am working on a class assignment that is due next week. I can complete the assignment without any problem using the console as output, which is acceptable. However, the Professor also suggested we research JTextArea and consider using it for our program output.
I found some code from a tutorial and was able to at least get a text block to appear with my first line of text to appear. But as I write the actual program, I need to continue to add additional lines to the text block as the program progresses.
When I attempt to use the following line of code in the main method to display text line 2, I get an error saying, "non-static variable textarea cannot be referenced from a static context".
textarea.append("Product1\t3\t$3.01\t$9.03");
Here is the code I have so far. Thanks in advance for any help!
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
public class ta extends JFrame{
JTextArea textarea;
public ta(){
setLayout(new FlowLayout ());
textarea = new JTextArea ("Product\tQuantity\tLine Cost\tOrder Cost\n", 5,30);
add(textarea);
}
public static void main(String[] args) {
ta gui = new ta();
gui.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
gui.setSize(500,200);
gui.setVisible(true);
textarea.append("Product1\t3\t$3.01\t$9.03");
}
}

You can not reference textarea (which is a instance field) from a static context (ie from within main).
Instead, move textarea.append("Product1\t3\t$3.01\t$9.03"); to be within your constructor
public ta(){
setLayout(new FlowLayout ());
textarea = new JTextArea ("Product\tQuantity\tLine Cost\tOrder Cost\n", 5,30);
add(textarea);
textarea.append("Product1\t3\t$3.01\t$9.03");
}
Or provide some other "update" method for your ta class which you can call
You might like to have a read through Code Conventions for the Java TM Programming Language, it will make it easier for people to read your code and for you to read others

Project doesnt run main class

I have a small problem with Jform-Designer, I've made a Designer class (Jform class) and i defined that as my main class.
Like this:
class Designer extends JFrame {
public static void main(String[] args) {
Designer design;
design = new Designer();
design.initComponents();
}
private void initComponents() {
// JFormDesigner - Component initialization - DO NOT MODIFY //GEN-BEGIN:initComponents
//======== this ========
Container contentPane = getContentPane();
contentPane.setLayout(new FormLayout(
"9*(default, $lcgap), default",
"9*(default, $lgap), default"));
pack();
setLocationRelativeTo(getOwner());
// JFormDesigner - End of component initialization //GEN-END:initComponents
}
}
But the program doesnt run now, i think it is stuck in a infinite loop at this part of my code:
public static void main(String[] args) {
Designer design;
design = new Designer();
design.initComponents();
}
Can someone explain what i need to do to run the project properly.
Thanks in advance

It runs but you're not making the frame visible
design.setVisible(true);

What's Wrong WIth My Code involving JFrames

It's Giving me an error saying that "The method setContentPane(Container) in the type JFrame is not applicable for the arguments (GamePanel)"
Here is my Code:
package main;
import javax.swing.JFrame;
public class Game {
public static void main(String[] args){
JFrame window = new JFrame("Dragon Tales");
window.setContentPane(new GamePanel());
window.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
window.setResizable(false);
}
}
I am following a tutorial exactly and his screen shows no errors at all.

Your GamePanel class does not extend any Swing GUI component such as Container or one of its children. Probably it should extend JPanel.
i.e.,
import javax.swing.JPanel;
public class GamePanel extends JPanel {
// .... etc
}
Please don't add the urgent or "help as soon as possible" bit. Yes your question is very important, but it is no more important than anyone else's.
Edit: Mad's link is worth putting in the answer: The Oracle Swing Tutorial.

Different windows with the same code?

This is the "main" class (doesn't contain the main method)
import javax.swing.*;
import java.awt.*;
//import java.lang.Object;
//import java.awt.event.ActionListener;
//import java.awt.event.;
public class Program {
public JFrame frame;
public JPanel header;
public JPanel text;
public JPanel body;
public JTextField input;
public JButton agregar;
public List listA;
public List listB;
public Program(String title) {
frame = new JFrame(title);
frame.setSize(500,600);
frame.setResizable(false);
frame.setVisible(true);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setLayout(null);
header = new JPanel();
header.setBackground(new Color(255,204,50));
header.setBounds(0,0,500,100);
text = new JPanel();
text.setBackground(new Color(255,204,100));
text.setBounds(0,100,500,50);
text.setLayout(null);
//Inicializando la "entrada"
input = new JTextField(20);
input.setBounds(50,13,300,25);
text.add(input);
agregar = new JButton();
agregar.setBounds(360,12,80,25);
agregar.setText("Agregar");
text.add(agregar);
//Listo
body = new JPanel();
body.setBackground(new Color(255,204,150));
body.setBounds(0,150,500,450);
//Lo que está dentro del body
listA = new List(20);
body.add(listA);
listB = new List(20);
body.add(listB);
//Listo
//Añadir todos los paneles al frame principal
frame.add(header);
frame.add(text);
frame.add(body);
}
}
And this is the MAIN class (This one contains the main method):
public class Main {
public static void main(String[] args) {
new Program("Ordenamiento Recursivo");
}
}
Each time I run the application, the UI components are presented differently, please see attached screen shot.
Well, thanks to everyone who responded the post, I finished the program and I'm very happy with the final result, here it is:
In case anyone wants to take a look at the code, here it is: Link

Problems:
You're call setVisible(true) on your JFrame before adding components and this will lead to unreliable drawing of your program's graphics and is why you are seeing different results. Don't do this, but rather call it after you've added all to the top-level Window.
As the others are saying, read up and learn to use the layout managers.

Different windows with the same code?
I think that is very simple and possible by implements CardLayout
I'd suggest don't opening a new Top-Level Container, only if is there really important reason then use JDialog or JOptionPane

Be sure to construct the GUI on the EDT. Not doing so can cause unpredictable results.
Call pack() after the components are added using layouts and then call setVisible(true).

You will need a layout manager for your form so setting the layout manager to null is not the thing to do.
Work in progress here ... https://gist.github.com/2510570
Couple of changes. Not quite finished yet, but check out the following
Have Program extend a JFrame.
Have set a layout manager.
Update
Finally I knocked this up in IntelliJ's form designer.
https://gist.github.com/2512197
Where you want to attach behaviour to the buttons search through the code for the comments that ask you to add code. Although I did this in the InteliJ Ultimate (this one that costs money) I think that no-cost free to download Community Edition UI designer also paints Swings GUIs. Very quick and easy. Netbeans also has a good GUI painter.
The Swing Tutorial on oracle.com is worth reviewing also.