Linux but neither Fedora nor Ubuntu I would suggest. Fedora is not a good fit for server I believe and Ubuntu the worse Debian.

I tried it and it was nice but ultimately I switched to apprise

I strongly suggest to not only read articles on the internet but get decent books and read them carefully. It will fill in plenty of gaps you have now and in a blink of an eye self-hosting will become a smooth and fun experience.

I have been self hosting for like 20 years and I must say it has never been easier to bring up a service and make it secure as well.

Good network understanding is key, forget about IPv4 it’s dead. If you engineer new stuff, concentrate on IPv6. Also a good book or two about Linux, it’s the platform to go for the next decade. If you’re still hungry dive into containers and container orchestration.

Most importantly, keep experimenting. I’d say 80%+ of my empirical data comes from my own experience.