Screen protector is the most important. only that , but you can buy a protection case.
I recommend that only play the Nintendo Switch in home to prevent theft at school or public places, if necessary, only the travel protector.
Yes, I recommend that you buy the screen saver at once and put it in the store at the time of buying the Nintendo Switch, I recommend that you buy any screen protection compatible with Switch, it is not necessary the Nintendo official , because they are the Same quality and are more expensive.
And Games: Zelda Links Awakening, Luigi Mansion, Mario Oddysey, Yoshi Crafted World
Low cost games of 30$ less that i recommend: Harry potter Collection. A time in Hat.
Ok, im exaggerating about the trash can but I personally wouldn't recommend the switch lite if you already have a more capable system. The library just isn't doing it for me. Of course, different strokes and all that. As for the OP question, I didn't find a need for any accessories. Just my 2 cents.