I have two instances running debian on a lenovo think-something-or-other mini pc and a no name mini pc. Both are set for auto-login, and both fire up plex-htpc by default. I use a $10 remote I got off amazon that is "normal" on one side, with qwerty on the back. It also has a button you press to enable/disable a mouse cursor that you tip the remote around to control. Works well enough, and an old wireless mouse/keyboard stays tucked away if I ever need to do any real work on the system.

There were some annoying audio issues with Debian I fixed by nuking/reinstalling, but other than that it works pretty well as long as you know/are willing to learn how to write some scripts to auto-start some things. Plex-HTPC is 95% of what I use, the other 5% is using the browser to launch an owncast page that I stream... my bird-feeder... to for friends and family when they can't access... my bird-feeder... in their market. It's worth mentioning plex has DVR options if you're willing to go that route.

Tl;Dr: Base regular setup of your choice as others are recommending, $10 remote off amazon, some scripting for start-up and some shortcuts on the desktop. I do recommend paying a bit more for a remote where the keyboard is backlit.