I've been playing with NixOS in spare time for a few weeks now and I'm afraid I don't have a very good news for you. It looks like the learning curve is just very steep. It took me quite a lot of time to get to the point where I have any idea what I'm doing. Some beginner friendly resources which helped me:
-
Misterio77 Nix starter configs and his own config.
In general, I recommend checking out people's configs on GitHub. You can learn a lot by example.