This section covers the basics: functions, variables, and if statements. These are important concepts that programmers use every day, so it's important to have a solid understanding of how they work.
By the end of this tutorial, you'll have a simple but useful base that you can use to build many types of games from. Don't be afraid to experiment! Use the all of the example code in these tutorials along with the Processing API to play around and get interesting results! That's the best way to learn, so I suggest stopping for at least a few minutes and modifying each example to see what happens. These tutorials are meant as a starting step- actually diving in is up to you.
Next: Calling Functions