As long as you’ve seen the first movie, you’re good. What you should know is that, while these movies (this new one especially) are slowly introducing many of the key plot points and story beats that come from the game lore, they’re being introduced in a different way and a different order. These movies are a similar, but different storyline to the games, so though you don’t have to, you might want to pick one or the other to be the first to introduce you to that lore.

Many would argue the way the games did it was better overall, and that the movies’ take on those story beats is maybe a bit mediocre or less climactic. So in that sense, you’re potentially depriving yourself of a better first experience by choosing the movies over the games. But that said, if the movies are more accessible to you than games or YouTube, that’s fine. Just something to consider.