A) I know almost nothing about them
B) I'm a nincompoop and forgot Marvel doesn't make bad movies.
Let me rephrase. I never forget Marvel doesn't make bad movies.
I did forget, amidst everything going on, that Marvel always makes movies that take full and excellent advantage of a large screen and amped up sound system.
It was visually stunning.
There was a huge cast of varied characters that were all interesting, complex and fun to watch.
The story had all sorts of twists and turns, spread over a hugely epic time period. which led to a satisfying ending that leaves many cool things open for follow ups in sequels and other Marvel films.
Much like Shang-Chi, it was a boatload of new and fresh stuff that still fit very well in the existing Marvel Cinematic Universe.
Introducing that many characters in one story could be troublesome and confusing. However, this group let the MCU use the trick Stan Lee did when he created the X-men with Jack Kirby. Instead of coming up with varied origins for everyone in the group, he said they were all born that way.
"Born" may be a little off the mark for Eternals, but they all got powers the same way and came from the same place. Therefore the origin portion for everyone was covered quickly (…so we thought...) and the film could focus on story and character development.
I've written regularly about how, as the MCU gets more complex with crossovers and alternate timelines, normal people are getting to experience what we die hard comic fans have been following and enjoying for years.
Eternals was a very cool switch. It allowed me to experience a Marvel film like normal people do. At least after geeking out about a minor character in the beginning being someone I have many comic book appearances of and also an action figure of.
After collecting comics on a nearly weekly basis for well over thirty five years, and being a fan of various characters in multiple media for at least a decade before that, this is what I knew about the Eternals going into the movie:
They were created by Jack Kirby on his return to Marvel in the Seventies.
They were connected to Deviants and the Celestials.
There was some connection to Starfox (who was in the East Coast Avengers when I was collecting the West Coast Branch) and his brother Thanos.
Gilgamesh joined the Avengers in an anniversary issue I have from shortly after the West Coast group folded. (I did not know he was an Eternal at that time.)
Sersi, who I did know was an Eternal, joined the Avengers after that, when I wasn't reading them.
I thought Deviants were humanoid in comics (they are), but wasn't sure enough to question it when they showed up.
That's about it.
And I knew one was named Ikaris, but because I missed the general mythological connection of all the Eternals, I thought it was not pronounced like the Ancient Greek guy who flew close to the sun, but Eye-kar-us.
It was a refreshing and fun experience going into a comic book movie with NO preconceived ideas and just enjoying whatever was happening and letting it wash over me.
Is this how normal people experience these films?
Final note: The Celestials were IMMENSE and AWESOME and MAGNIFICENT LOOKING.
Well done Marvel, you've proved you can do Galactus.
Lets get the Fantastic Four on those screens and build up to the next giant threat to come after Kang.