Hello,
I encourage you to look at the resources available here:
Beginner
-
The Processing website has references, examples, tutorials, etc.
https://processing.org/ -
The Processing PDE (IDE) has lots to offer!
An exploration of the menu items will reveal what is available!
You will find libraries, tools, examples and more!
For example:
-
The Coding Train
https://www.youtube.com/channel/UCvjgXvBlbQiydffZU7m1_aw
https://thecodingtrain.com/ -
Happy Coding
https://happycoding.io/tutorials/processing/
Advanced
-
The source code can give insight if you are adventurous:
https://github.com/processing/processing
Many of the Processing functions are here:
https://github.com/processing/processing/blob/master/core/src/processing/core/PApplet.java -
And the Internet.
When you are ready explore for() loops :
https://processing.org/reference/for.html
:)