No reason other than the fact that you need extra steps to get Jellyfin working in Fedora.

If you have the patience and time, as I mentioned, you can still use Jellyfin in Fedora.

Debian, Ubuntu and Fedora should be good (in that order); I'm not very aware on truenas to give an opinion, but it seems it will work just as well from other comments.

I personally use Fedora, and it's been a solid experience too, with the only gripe bring SELinux. I required a fix for SELinux, but it has worked flawlessly since.

However SELinux might make it annoying to work with containers, so you could consider either switching it off, using another distro or using appropriate configurations to work with it correctly.

Coding is bit hit and miss. Long back I had used unity and c#, (both were new to me). As of recent, I’ve been trying to learn godot and c# since I’ve played a few 2d games. Maybe these would be a good starting point. You may find other engines that require less to no coding as others suggested to be better.

Comics could be funny, informative, or maybe just an “today was interesting” thing, or even introspection. Anything that feels interesting to you.

Videos are even more open, you can make videos on a lot of topics, anything you find interesting, anything you want to teach, and so on. Gaming videos are also nice, once you’ve started you can learn a lot and settle on something that you’ll like (what you play, how you play, how you communicate with your audience,…). There’s two big places - YouTube and Twitch. Both are I’d say good places.

A low end computer should hopefully not be a dealbreaker for you, it should be a good way to start. If you’re worried that is the case, you can look around and confirm if it can be used to start.

Photography - added benefit is that you will usually go out for this

Music - an instrument is good

Drawing/Painting

Programming (hit or miss, I found learning unity was fun)

Video making - recording video games playthroughs, cooking, and so on.

Finally, one that usually everyone probably also may mention - Therapy - not a hobby but having to be able to talk about it is often good

This is of course not an exhaustive list - but it depends on what your interests are. Hope this is a good pointer to what you’re looking for.