I'm where you are right now. My puppy will be 12 weeks old tomorrow. I've read tons of websites and watched many videos on youtube about all different kinds of training to stop the biting among other things. It's my main concern right now.
Some say to put a toy in the puppy's mouth when he tries to bite, but that only goes so far with pit bull puppies. They're far more determined than any other breed I've known. I don't know what breed you have, but it doesn't work very often for me or he'll take the toy out of reach and go back to biting myself and my husband. He doesn't bite hard, but those baby teeth are like little razors. When he was still teething, we bought him a puppy kong. They're designed to give their gums some relief and it did help. We bought the Kong Stuffin (peanut butter or cheese works well and is less expensive), but when we put some in his kong, he'll leave us alone for a little while. That also helped with the whining. Your puppy's little gums might be hurting him now. Squeeky toys help get their attention focused on something other than you to bite. Other things you can do is stop playing the minute he starts biting or put him in a "time out" until he's calmed down. It doesn't work for me, but it could work for you.
Potty training is definitely a hard one. My puppy is getting a little better, but he still goes in the house. They need to be watched at all times. For the past month, I've been sleeping on the couch with him so I can take him out during the night to avoid accidents. Generally, we take him out the minute he wakes up, minutes after he eats or drinks and in the middle of play time. One of us keeps his attention while the other grabs his leash to take him out when he wakes up. You basically have to watch for his signals that he has to go outside. Every puppy has different signals, but they all will sniff around the room looking for a place to go. Biting could also be a signal. Mine wakes me up by biting my hand to tell me he has to go. Puppies that young should really be going outside at least once an hour. Their bladder is so tiny at that point and they haven't learned how to control it yet. Taking his food and water bowl about an hour before you go to bed will help with the night time accidents. Praising is a good thing, but he needs to be taken outside more often in the beginning. He will learn, but it takes time and a whole lot of patience.
I'm guilty of it too, but try not to hold him so often. My dog died a little over a month ago. When we got him, he was a rescue and no longer a puppy. All I wanted to do was hold him, but I never got the chance because of his size. My grief continues to get the better of me. Not only because I'd give anything to have my boy back, but because this puppy looks almost exactly like him and has some of his personality traits. It doesn't help we got the puppy the day after my angel died. I held him quite a bit that first week, but I fight the urge now knowing that he'll be huge when he grows up. At 3 months old, he's twice the size of his siblings and other pit bull puppies I've seen at his age. Try laying him down next to you instead. He'll get used to that and won't try to curl up in your lap when he gets bigger. Depending on how big your puppy will get, it could become a problem.
Good luck with your puppy and please remember to be patient. Basic training doesn't happen over night.