I recently started reading more books and really enjoy it. My only problem is, there is so much choice, I feel overwhelmed. At the moment I just read some random books that I got for free from someone.

It’s normal to feel overwhelmed as there is an almost limitless amount of books to chose from. The best advice I may give you is to talk to your local library. Most librarians are more than happy to help a new reader find their bearings (based on what you think you might enjoy, say scifi, or fantasy, or romance, or biographies, or whatever), no matter your previous (lack of) experience :)

In the city there is also a public bookshelf. Does your city have this as well?

Library? We do (multiple ones), but I do live in a rather large city.

I also tried chess, but could never really get into it. I can never remember which moves I’m allowed to make with the pieces.

You will learn the rules by playing, there are not that many they’re just… arbitrary (like any rule). To learn the basics you can create a free account on chess.com and follow their beginner tutorial (there is no need to subscribe to one of their paid plan), or you can use lichess.org (100% free, this time): https://lichess.org/learn and then you can start playing against players or bots (at least on chess. com there are bots for absolute beginners to play against).

The one tip as a beginner that is just starting is to be ok with losing a lot of games. That’s to be expected, don’t take it personally. That’s how most of us learn… anything, by failing and by being bad at it to begin with ;)