What are some things to host as a beginner? (pihole, minecraft and home asssistent already installed)

I want to get into the world of selfhosting.

Bought a NUC with 16g of ram and already set up pihole, minecraftserver and home assistent.

But there are so MANY services you could self host...sooo what are some nice recommendations?

Thought about calibre web for my ebooks and maybe mextcloud, but apart from that, i dont know where to start. I dont have many movies or music, so thats crossed out.