Golden retriever growls aggressively when playing with toys

IMO you're overreacting. That's pretty natural behavior.

lol, I wish my dog were that chill when playing. She's normal.

Another vote for "looks pretty normal to me". One thing you will want to do, though, is teach her to drop something on cue. Kikopup has lots of free training videos on YouTube.

Yep, totally normal and adorable puppy behavior. My adult dog still plays like that; she growls when she plays with my other dog, but it's that very adorable high-pitched voice. Your puppy is not aggressive. She's just examining her toy and having fun with it.

What you might want to do, though, is to make sure she doesn't learn to tear fluffy toys apart because then every plush toy will only last minutes. So as soon as she tries to dismember toys, take it away.

I made a mistake of letting one of my rescues destroy plush toys, and now she kills bunnies outside, which is totally unacceptable.

Basically, teach her to respect toys. Other than that, your puppy is totally normal.