Well technically viscreals/gun parries are pretty new. There was a parry mechanic in Dark Souls but it's obviously not tied to guns since there's no gun, and ranged weapons can't parry, it's just traditional game parry. Shit makes a lot more sense too because it uses the same button as blocking with a shield, and can be done either with parrying shields or a weapon, so it kinda like a natural concept. On the other hand Bloodborne stuff makes no sense whatsoever unless you know about it. Might be written somewhere in the super short tutorial though, maybe? I forgot.
Do watch mechanics videos, weapon comparison and shit like that. Just don't watch a walkthrough, since that ruins the exploration and discovery aspect of the game, I think that's more what he meant. I mean you can play without checking mechanics too, but I know I tend to always read up the wiki shit on the games when I start them, I want to know what the stats do exactly, how the upgrade systems work in each games and such stuff. Helps me plan my stuff from the start(although it's mostly dagger/rapier builds, love the fast hits).
Also the gun parries aren't really necessary. I think I only used it a few times the entire game, as I disliked how it was tied to non instant projectiles and all that shit, I liked parries a lot more in dark souls, even though they're like A LOT harder to time correctly.
