Umbrella evil. There, that’s pretty much your catch-up on every game’s story.
I guess it gets confusing with recent remakes of 2, 3, 4; they’re meant as clear entry points, and the latest version of RE1 is still a bit old (though it too is a “remake” of an ancient PS1 edition)
7 is extremely different from the others - it was even thought to be a new/different IP when it was revealed. Village is a direct sequel to that, but could also be enjoyed alone; it’s a bit more action and less creepy.