Exercise. Establish a good sleeping routine and stick to it. Eat well

Because you’ll get your deck and probably spend too many nights just slipping into deck time and discover it’s one am.

If you get ahead of that now then you should be OK.

I know you already mentioned waiting till you have an SD card but look into something like tiny best set if you don’t have a lot of experience with retro stuff.

It’s less about specific games and more about your mindset in games. What kind of games are more just fiddling with your hands? For some that’s tetris for others its Diablo and some it’s fortnite