Since less techy people tend to use more the mouse/touchpad anyways, I would pick a hard-to-mess-with desktop environment like mint or gnome. With KDE, XFCE and such you can screw panels really easily if you don’t know what you’re doing.
Slap Debian under it and there you go

Welcome to the team.
I hope you brought your boincing shoes because as soon you’ll get comfortable you’ll start hopping a lot