Hi Dorae,
It is VERY normal. This will go on for ages, as well, hes mouthing, he doens't know hes biting, thinks hes playing like what he did with his litter mates.
First thing i suggest is get yourself the 'The Perfect Puppy Book' by Gwen Bailey. I would get this NOW, if its your first puppy, so you know what to expect, and how to act around him, and how to show him what he should and shouldn't be doing.
It will teach you to ignore, the bad behaviour - NEVER to punish it.
As a start, when the pup mouths you, try and occupy him with a toy, or get up and ignore him.
As you have a big family, its a great opportunity for you all to leanr, and if you go through the book together, you will all be working with the same goal.
You are very lucky to have this time, with your young pup, do enjoy it.
I assure you wyou will have lots of time, when y ou despair, but its all worth it, and there are lots of people on here to advise and help.
WHats his name?, Can you post pictures.
Please do buy the book, its invaluable. !!!