welcome to the ranch
what about writing the classic "hello world!" program, then write a class HelloWorld and instantiate it from another one (your controller)?
Then write a class HelloNatalie that inherits HelloWorld, have a look at shadowing and overloading...
Write an interface Animal and classes like Cat and Dog, create collections of animals (lists, arrays etc) of animals, give them attributes like 'likes milk', use iterators in loops to make them all meow and bark, select only those that like milk etc.
Have a closer look at Java AWT and Swing graphic APIs and create a new window (JFrame) with some area to host your game, the board (JPanel or Canvas).
Draw a circle on that board. Have look at the APIs default passive rendering (paintComponent()) and learn a bit about active rendering.
Introduce a timer and have that circle moving from left to right. When you can do that, make it bounce back from the left and right (boundary detection).
Then introduce angles and have that circle bounce back from top and bottom of your board, make it disappear when going over left and right boundaries...
Have a closer look at KeyListener and/or KeyAdapter and draw two rectangles, one left one right on your board.
Control them with your keyboard (up and down with boundary detection at top and bottom) and make the circle bounce back from the rectangles (collision detection).
Enjoy playing Pong!
Don't start with making it look nice until it does what you think it should be doing. Once it works, learn how to load images etc. Introduce a high score list, store that in a text file or embedded database.... Make your game configurable.
Then have a great idea, get the basic shapes moving (circles and rectangles), make boundary checking and collisions work, make it look nice and earn a lot of money