you haven't provided enough info. each puppy is individual and you can't judge by breed alone.
generally pit bulls are happy, friendly dogs. labs are too. i've never been bitten by a pittie but have been by 3 different labs. Basically a dog is a product of it's environment. a puppy turns out however it's owner teaches it to be. One of the labs I was bitten by was abused. several pit bulls have been abused too but never bit.