I'm a DC comics nerd at the detail level, but for Marvel I'm more at the "general knowledge" nerd level. She was one of my favorite characters in the Marvel Heroes MMO action RPG (may it rest in peace). So I know who Captain Marvel is, and some general stuff about her origin, but not chapter and verse of every little detail. Between that general knowledge and promo material like the trailer, I found the movie to move somewhat slowly as it went through lots of setup about the character. Par for the course with an origin movie, so I was prepared, but still a little boring.
The good news is that even knowing what's coming, Captain Marvel is still entertaining. I liked Brie Larson's performance, they did a good job cutting 25 years off Samuel L. Jackson's look, and the supporting cast does a fine job. (Particularly Ben Mendelsohn as the Skrull leader.) I loved the costume they came up with for her, except that silly mohawk helmet thing, but I suppose you have to give something to the traditionalist comics people. Lots of special effects eye candy, especially near the end. Which is only what I've come to expect from the MCU.
You're not going to miss the big themes of this movie. A determined woman overcoming "a girl can't do that" prejudice: not only do we see tons of this from the main character, you've also got her best friend, honorary niece, and even one of the top enemy fighters pounding that theme home. The fact that the timeframe is 20 years ago: if Blockbuster and Radio Shack isn't enough, there's all kinds of music and culture references scattered about. People aren't what they may first seem - spoiler territory, but it's everywhere. I have no problem with any of it, but be warned, don't expect subtlety.
There was a lot of hate for this movie across the Internet before it even came out, and that continued through the opening weekend. I'm happy to say those idiots were wrong; a female lead is just fine for a superhero movie (not that anyone who's seen Wonder Woman is surprised by that). I kinda wish the creators had gone further - imagine if they'd swapped roles for Larson and Lashana Lynch (who plays her black best friend). I bet the movie would be just as good, and would have caused even more coronaries among the kind of morons who hate on movies for who they feature.
I'd put Captain Marvel firmly in the middle of the MCU movie universe...solid effort that's better than some and worse than others. For an origin movie, it's hard to complain. And I really look forward to seeing Carol Danvers kicking some serious tail in future films.
