Your Pit Bull puppy has boundless energy. With such a little pup, you don't mind them jumping up on you when you come into the house. But in a few months, your puppy won't be so little anymore and with the bad press surrounding Pit Bull, your dog could easily scare a guest. Pit Bull are playful and they often show their enthusiasm by jumping up on people, so training your puppy not to jump is important for a well-behaved adult dog.
Puppies are eager to please, so training your Pittie not to jump should be easy if you start young. Your puppy is jumping on you because, in the past, doing so got them the attention they wanted. During training, your goal is to show your pup that jumping doesn't get them what they want. It should only take a couple of weeks for them to get the hang of it.
When training your Pit Bull puppy not to jump, make sure to set firm boundaries for your puppy. Jumping can't get any reward, from you or your guests. Even if your guests say they don't mind the jumping, attention from them will just make your job more difficult. You should do a short training session at least once every day, but keep in mind to practice the skills whenever your puppy jumps.