1. It is a very bad idea to study by reference to the language. You need to learn from examples, and not sequentially studying variables, types, loops, conditions, function, procedures, and so on. You will spend a lot of time on this.
2. It is good practice to convert your code from one language to another. For example, from the Processing language to the FreeBasic language. There is a great free book on the Processing language,
The Nature of Code (
https://natureofcode.com/book/), start with simple examples and try to make your code work in FreeBasic.
3. Also, an excellent example is the site
http://www.rosettacode.org/wiki/Rosetta_Code, which contains examples of code in 836(!!!) programming languages, including FreeBasic. Choose
Explore -> Languages in the menu, find FreeBasic and go!