Bots on Wheels FRC 4290 Programming Documentation.
This chapter of the book will be going over various basic topics on programming using Java, which is one of the programming languages that WPILib supports.
WPILib is the official library for FRC. In programming, a library is a bunch of reusable code made to make developing certain things easier, in this case, programming robots.
The official first documentation has a great guide on installing WPILib that can be found here.
This installation will include: WPILib VSCode, The correct version of Java, and a few other things. VSCode is a lightweight code editor, and although not necessary it is recommended to use the WPILib specific version of VSCode as your editor when editing robot code.