My advice if you don't have the time or wherewithal to watch all 22 movies right now (who does) would be to google the story itself and that would give you a good introduction to End Game. But.......for many of us it's not just the story but it's also the performances of the entire repertoire and their intertwining relationships that mean as much or even more.
I can take my time. I have 3 kids, 2 of which are into these types of things. We watched all the Harry Potter’s so we can take it slow and try to enjoy. Glad to hear I can miss the hulk stories those never really interested me.