I hear you with the "many ways to do things". The flexibility in the language to get from input to outputs means every GIT I look at has differently constructed flakes. Finally, after pouring some time in these last couple of weeks i am grasping the basics. Zero to Linux https://zero-to-nix.com/ was the first time it came together for me.
If you have a 3d printer also check out Klipper, Octopi etc. I run mine off a pi zero 2 and it is a leap in performance over the stock board on the Ender 5.