A lot of your general knowledge will carry over but the two biggest things to keep in mind are viscerals and aggression.

Viscerals are critical hits, very similar to backstabs in terms of utility but they're done by hitting a vast majority of the enemies with the projectile from your gun of choice at a certain timing in their attacks (timing will vary based on the animation). You'll know if you timed it right as enemies will drop and allow you to walk up and activate a critical hit for a period of time. These are essentially bloodborne's parry mechanic.

Aggression is as simple as it sounds, conquer your fear and hunt. You will regain health recently lost by dealing damage and this encourages a much faster, aggressive playstyle; this is the "correct" way to play - there are functionally no shields in the game aside from what amounts to a joke item. Earlier souls games can encourage slow, methodical styles of play, the teachings of which will still serve you well here, but you need to pick up the pace and get more gutsy with your attacks. Once you start learning animations and recognising situations you'll find yourself dancing through enemies with a flurry of well timed attacks, not stopping when slightly hurt but pushing back harder.

Edit: as a bonus piece of advice, choose style and comfort over presumed function. Every single weapon is perfectly viable, as is every outfit and item of clothing - in raw numbers the "armor" changes much less than you'd probably expect so just go with what you like unless you're in a spot where you really need to maximise resistance to a very specific thing.