I have used gnome, plasma, and xfce and they are all fine. I prefer KDE personally but they’re all going to do what you need to do. It’s all down to personal aesthetic preference, and picking one won’t hinder you in any real way. KDE to me just looks super nice out of the box for my taste, and I like the customization.

I love Debian. Been using it on my laptop for over a year. Some specific drivers are a little fiddly if you have nvidia graphics but it’s not too bad, lots of good info on the debian wiki.