Everyone gave good alternatives for where to buy music. As for the pipeline for getting them into your music server, I have Picard running in a container (a couple projects do this, search docker picard) and I have the settings all configured so that when I drop in files to my NAS (though samba or whatever), then I just double click the folder in Picard and hit save and it moves it into my music server’s directories, all properly and nicely tagged (I have the container volumes all set up properly as well)
You can look into beets or wrtag for more automation friendly tagging services.
https://perfectmediaserver.com/ This is the guide that really gave me the confidence to take ownership of my self hosting. My setup now is simple (I use ucore from the universal blue project as a rock solid base) and I use small tools that I can understand (snapraid, mergerfs, borgmatic) to make things robust as well as podman and quadlets (docker also works great) to enable easily hosting basically anything I want through containers.