Fellow noob here, lots of great suggestions already. I agree with the “find a specific idea and start there” so you can be vested in what you need to learn.

I suggest starting with an old raspberry pi or other old hardware that may not get the job done, but fiddle with it toward your goal until you prove you can do it. It’s so rewarding!

Once that’s done, move on to getting whatever hardware you need to execute the vision well. Mechanics don’t start learning by working on a Ferrari!

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 :-)

Pick something you want to self host first. Do you want a media library? Then look into Jellyfin guides, or komga, or whatever. Do you want a centralized blocking dns server for all your devices? Look into adguard/pihole/etc. do you want to fuck around with llms? That’s a whole thing but you totally can and look into guides on doing it

Just as advice you’ll find people that become borderline evangelical on what you use. It doesn’t really matter. Debian vs unraid vs truenas, ecc ram or not, etc. I mean it does, somewhat, and you should read about it, but don’t get hung up on small details. For home use basically anything is fine. Get an old ewaste pc from 2012 and run whatever os you want (just not windows though)

You can start by using any old PC you have laying around and install Proxmox on it. Proxmox is a free hypervisor that allows you to make virtual machines and containers which makes it easy to setup and administrate servers/services. This will give you a good foundation to start playing around and give you an idea of your resource requirements.

Find something that interests you, and look at the docs of how to get started. It literally is the easiest way to learn and get involved in self hosting

Don’t have a good guide, but in addition on the thing you plan to selfhost yourself you need to decide where it’s supposed to run. In a rented VM from a hoster? There are several ones where you can get a decent VM for a few bucks each month.

Nowadays, Docker (or containers in general) are very popular, as an alternative to directly installing services on the vm. They make many things easier, but it’s another thing to learn about when you’re just starting - fortunately, there’s plenty of guides etc!