I think it is wise to use Nix for a bit before trying to manage all your user configs with it. Using `nix-shell` for project dependencies is a good starting point. You can't really make any costly mistakes here since the scope of any given project is likely much less than all your system and user configurations.

Nix shell plus something like direnv using flakes or nix expressions (non-flake approach) would give you a chance to learn the language and ecosystem. Once you feel comfortable with this, home-manager should be much more approachable.