Welcome to the family!
I’ve been using Linux for ~14 years and am not a computer person at all. Of all the distros, Linux Mint is by far the easiest, most intuitive, and works without problems. I think that the installation is even easier than Windows. There’s also a large supportive community in case you should into any problems, abd because it’s tailored for newer users, whatever problem you run into has likely already been resolved by someone else.
My personal favorite at the moment is KDE Neon tho.
Yeah, Mint will tend to be a little slower than Debian since Mint is Debian plus Ubuntu plus Mint. If you’re looking for speed, LMDE or XFCE desktop environments would be the quickest. Of those 2, LMDE might be faster, but it’s almost a bare bones GUI. XFCE might be just a little slower, but the GUI will be more adjustable.
Good luck!! 😀