I would recommend that you see Avengers: Infinity War at least before seeing this.
But you should watch all 22 movies starting with Iron Man in 2008.
Lolol... That comment has me rolling Erik.. Thanks! There are a ton of these comic book movies.
I find them entertaining in general with the exclusion of Spider Man which has had too many reboots..Imho.
For those who wish to get caught up, watch these Marvel movies in this order:
Iron Man (2008)
The Incredible Hulk (2008)
Iron Man 2 (2010)
Thor (2011)
Captain America: The First Avenger (2011)
The Avengers (2012)
Iron Man 3 (2013)
Thor: The Dark World (2013)
Guardians of the Galaxy (2014)
Guardians of the Galaxy Vol. 2 (2017)
Captain America: The Winter Soldier (2014)
Avengers: Age of Ultron (2015)
Ant-Man (2015)
Captain America: Civil War (2016)
Spider-Man: Homecoming (2017)
Black Panther (2018)
Doctor Strange (2016)
Thor: Ragnarok (2017)
Avengers: Infinity War (2018)
Ant-Man and the Wasp (2018)
This is the order they advance the plot, NOT the order in which they were released.
You’re welcome.