It’s honestly probably better if you don’t know anything about the characters. Caitlyn and Vi are pretty different from the game and really the only deep lore cut you’d miss is the Brackern crystals, and that’s probably going to be spoilers for season 2.
Not at all, LoL’s lore gets retconned so often that Arcane is basically it’s own thing but with borrowed ideas.
It’s honestly probably better if you don’t know anything about the characters. Caitlyn and Vi are pretty different from the game and really the only deep lore cut you’d miss is the Brackern crystals, and that’s probably going to be spoilers for season 2.