I don’t really understand how to subscribe to an instance that is hosted on a different server?

Like say I want to subscribe to this instance https://feddit.de/c/600euro how would I go on about not just being able to see it but have it in my feed too?

Which app is most like RIF? I’m using Jebora currently.

Vampire Survivors for sure! It’s a very chill arcade game and it’s like 2-3€ when on sale.