My 4 month old puppy won't stop biting EVERYTHING - is this normal??

I just got a golden retriever puppy about 3 weeks ago and oh my god the biting. My hands look like I fought a rosebush and lost badly.

He bites my hands, my feet, the couch, the table legs, my shoelaces while im trying to walk... literally everything. I've tried yelping like they suggest but he just gets more excited. Tried redirecting to toys but he goes right back to my hands.

Please tell me this is normal puppy stuff and not a sign I have an aggressive dog? When does it get better? Im exhausted lol