Oh and also Black Panther omg! That one isn't *the most relevant* for Endgame but it has two big advantages over some of the others:
-It's currently streaming on Netflix
-You get glimpses of a bunch of series characters so you can see how hot they are but this movie is mostly introducing a new set of characters so it's comprehensible even if you haven't seen any others.

So tbh I'd recommend starting there!