librePhoenix’s NixOS playlist is a great starting point imo. It’s been a while since I went through it so I don’t remember how much of it applies to using nix on a different distro but I imagine the home-manager video should still be relevant.
I’d also recommend jumping straight into flakes, it’s what most people use so there’s more resources and you may find that the only way to get something you want is through a flake, which is no big deal if you’re already using them.
Vimjoyer also makes good videos but I occasionally found myself lost trying to follow along, which was never the case with librePhoenix. That could just be because I’ve got no programming knowledge though.
Day going soooooo fucking sloooooow aaaaaaaaaa