Hi and welcome to YT! I'm so glad you found YT as you will learn a lot for all the knowledge of other members here.
I too had to bring my puppy home early (at 8 weeks). I think some of the "backyard" breeders (not all mind you) try to get their puppies out of the house as soon as possible so they don't have to care for them longer.
Our Princess Sophie, now almost 4 months old, is still biting, partly due to teething and partly from puppy exuberance. We tell her "no bite" and it does get her attention. I also know that if they do this and you ignore them, they soon get the message and will learn that biting is not acceptable. I also see that others have made suggestions as well that are very good. You will figure out what works for your puppy. Must remember though they they are puppies and their attention span is about the size of a nat. LOL
You are certainly doing the right thing by looking for answers here. You will learn a lot from the questions others are asking and there is a great "Library" for more specific questions that have already been answered. Enjoy looking around and please stay in touch. We are happy you decided to join us!!