When did you start to "parent" your baby?

I feel like this is such a silly question and as a FTM I'm probably overthinking it. When did you start to correct your baby's behavior? For context we have a happy, yet strong and rambunctious 8 months old. He loves to aggressively grab our faces/nose but I've started to pull his hand away and say "No gentle hands" and of course he probably has no idea what I'm saying but it hurts so bad. It was cute at first when he'd caress my face. Today my mom was holding him and he just squeezed her arm and she said ouch. Yes I get it he's a baby but that's why I'm asking. He also has started to crawl and pull up on things and yes it's baby proofed but some things I just say "no we're not doing that" and redirect him. I'd love to hear other parents thoughts.