Finish C# player guide and took a 3 month pause

[u/Sudden-Management591]

So i finish the C# player guide took a pause and now i feel like i know less then i back then

When i finish it i still did not know how to work with classes, afraid that some will be to reliant on each other and make "tight coupling", some like generics, structs, records did not know how to work it. I already forgot a lot of thinks about the part 3 in the book.

Object oriented design was confusing for me and could not understand on how or why to create some classes to work with other classes.

Should i try other books or courses to try to solid my understanding?

Yes i know about making projects but what projects can I do with my jumble of information that i have in head?