I HIGHLY recommend forking a nix-config that uses flakes, home-manager, and whatever window manager you prefer. Since Nix is so versatile (and the documentation of flakes and home-manager are BAD), I found it absolutely crucial to reuse a well-architected config and slowly modify it in a VM to sketch out my config until it was stable enough to try on a real machine.

Since I’m the NixOS guy, I recommend GUIX. 😉

This is how we used to do it before we had NixOS with impermanence mode. https://nixos.wiki/wiki/Impermanence