Welcome to the deep rabbit hole :-) how much do you know about how computers work? In general, you’re going to need to understand some basic networking and general Linux administration, but if you already have a grasp on that then I’d say you just need to start small (simple service, aim to have a resilience goal with backups and restoration) and other metrics that motivates you. Perhaps you want to learn something new with every service you host? You decide, this is your hobby :-)

Hey, don’t forget unciv :-) it may not look amazing but that game is a very fun 4x to play.

This is a very solid (if not the best) roguelike to play on phone.