Welcome! i3 is fantastic, and the Endeavour defaults I think are a great starting point. If you like MATE, both it and xfce can actually mix i3 within it if you don’t like pure i3. That could be something that may peak your interest. I haven’t specifically done a lot with MATE-i3, but if you are interested in xfce-i3, this could be something for you to try out. I also almost always end up with xfce4-panel on top of my i3 setup if nothing else.
Welcome aboard in sunny Italy! Coming from Arch, I think you’ll have an easier time than those who choose EOS as their first distribution. The forum here is very friendly, I think you will also have useful posts based on your previous experience at Arch.