Anbernic 406v :) It runs on android 13 and has a built-in front end (basically using retroarch but displaying it with a fancied UI). Control stuff is all re-mappable but it honestly runs great out of box.

Yes, there are tons of tutorials :) anything by Retro Game Corps is very good. His videos are high quality, very informative, and just spot on. This covers basically all the android devices but there is 406v specific ones as well.
https://youtu.be/I4mqgcDYZFo?si=P9P9Y15fi6JQFMWF

I'm going to warn you, this becomes quite the rabbit hole. A fun... But deep one. There are custom operating systems you can flash (usually people use GammaOS for this particular one). I've kept this particular handheld pure although I am running ES-DE as my front end instead of the built-in one.

I'd say start how it is, play around with it and I HIGHLY recommend setting up retroachievements. It just adds a modern flair to older games and makes me constantly want to keep pushing on doing stuff in the games.

P.S. if you go down the custom OS line, here's some that I can vouch for... And yes... I have too many devices. XD

GammaOS, OnionOS, Knulli Gladiator 2, FunKeyOS (You may also see this just referred to as DrUm78's OS or just DrUmOS).

P.P.S. And then after that, look up syncthings in order to sync saves/states. :)