You should remove the nvidia drivers. AFAIK leaving them on won't affect the AMD GPU, but no sense in keeping them if you aren't using them.
AMD's open source drivers work perfectly out of the box and come with the mesa package which comes packaged with most Linux distros, so it's pretty much plug and play.
Just some FYI notes : Arch purists might get upset if you ask for help with Arch-derived distros (like Endeavour) on their forums. Also, RTFM. Check if https://wiki.archlinux.org/ has clear answers before asking online. Learning for yourself is always better than being spoonfed