Selfhosted

I recently set up a small home server and started trying to self host stuff. I found it pretty hard to get started. People have been very helpful on this community and other public forums, but I'm afraid it's often not enough. They give me advice in trying this or that, doing this and avoiding that... but I still don't understand more than half of the concepts that they use. I consider myself tech literate above the average user: I recently switched to Linux (after years on MacOS, using the command line, and even building a couple of programs from source), I also installed a custom ROM on my phone. I feel comfortable learning and doing these things... but still felt very very lost when trying to self host a few services. At the moment I settled for a local-only network where I run Jellyfin, Navidrome and Syncthing on OpenMediaVault. I'm lost with what I'd need to do to access my server from outside my local network, and terrified of doing something wrong and leaving a hole open so any hacker can access my server. I'd like to do it some day, but I'd rather have a safe local network than screw and get my data stolen or deleted.

So, in my opinion, we would need good tutorials or a MOOC to explain the basics from scratch.