When & In What Order Should Kids Watch Marvel Movies?

Being home 24 hours a day, my kids have had significantly more screen time than they did pre-quarantine. They watch shows like The Masked Singer, American Ninja Warrior Junior, and Lego Masters (and watch each episode several times) and Luigi (2 & 1/2) still enjoys Paw Patrol and Sesame Street. The Moose (9) and Pedro Tulo (6) will often join him with these "kid" shows, though usually with a tablet in their hands. The older two found a Nickelodeon show called Paradise Run, where three teams of kids around ages 11-14 race all over a Hawaiian resort, but I've found that if you've seen one episode, you've seen every episode. They also discovered Wheel of Fortune and Jeopardy! which resulted in this brief exchange:

Pedro Tulo: Is that a princess?
Me: No, that's Vanna White.

I mentioned recently that we let the kids watch Spaceballs. While The Moose said that he liked it, he definitely didn't get the jokes.

Anyway, I'm trying to expand what they watch. This got me thinking about the Marvel movies.

I am one of about 27 people who hasn't seen many movies in the Marvel Cinematic Universe. I really don't have an explanation why, but my best reasoning is that I haven't been to the movie theater much at all since my kids' births. The movies I've seen are those that are tangential to the main story but seemed to get good reviews (and were available during some free movie channel preview) such as Guardians of the Galaxy, Ant Man, Deadpool, and Spider-Man: Homecoming. With more free movie channel previews and just airings on regular cable, I started recording several of the movies. All of this leads to my questions in the title of this post. Are my kids old enough to watch the movies? If so, what order should we watch them and do we need to watch all the films in the series?

Oh, if you have other suggestions of TV shows and movies for my boys, please feel free to leave this in the comments too.