Many of Marvel's biggest characters came together in the 10-year in the making Avengers: Endgame, and because of that, it featured many first time meetings. That included Captain Marvel meeting Spider-Man, Valkyrie meeting The Wasp, and more, and fans ate it up with a spoon. That said, it does cause some fans to look back at the way things worked out and wonder why certain heroes hadn't met before them, and if you're going to ask a question, you might as well ask it to one of the engineers of this whole Marvel Cinematic Universe thing. That's what one fan had the chance to do when Guardians of the Galaxy director James Gunn opened up his social media feed to questions, and one fan asked: "Why Captain Marvel has never met GOTG before Endgame?"
Gunn had an answer, and it really comes down to how big the universe is, something films like Guardians of the Galaxy Vol. 2, Thor: Ragnarok, and Avengers: Infinity War really shined a light on.
Gunn said "There are sextillions of sentient beings in the universe. It would be unlikely they had met." It's concise and to the point, and if you think about it the only reason Cap returned to Earth in the first place was the pager she gave Fury, so if not for that she might not have known what was going on with Thanos and the Stones in the first place, so that seems plausible.
Gunn will return to the MCU with the anticipated Guardians of the Galaxy Vol. 3, which will have some new wrinkles thanks to Endgame, mainly centered on Gamora. Gamora is not the Gamora fans have come to know in the first two films, as the one we get by the end of Endgame is from before she had her adventures with the Guardians and before she fell in love with Star-Lord, so that is going to be a huge storyline for the third film once Gunn is finished with his Suicide Squad responsibilities.
As for Captain Marvel 2, while we don't have a title, we do know it will take place in the present day and will feature WandaVision writer Megan McDonnell on the script. Marvel is also looking for a woman to direct the film, as Anna Boden and Ryan Fleck won't be returning for the sequel.