Both KDE and GNOME are good DEs (and there are many other great ones, and you don’t even need to use a DE; a mismash of applications with your compositor of choice works just aswell - but I digress), you can’t really go wrong with either.
For someone new to Linux, I would likely recommend GNOME, because it is more opinionated. While KDE is a lot more configurable, that also has a huge downside: configuration fatigue. GNOME is more restrictive, yes, but that has the advantage of not overwhelming you right out of the box.
If you like and wish to tinker, though, go with KDE. If you want to gently ease into Linux, go with GNOME first, and once you’re comfortable, you can still experiment with KDE. You can install both, and switch between them simply by logging out of one and into the other.
I have Emacs, and I have my NixOS configuration. That’s all the GUI system configuration I need.