Hi You don't say how long you have had him - but when I got mine at 14 weeks he bit me hard at times simply because he didn't know it hurt me. Try to keep calm, say a really firm 'no' and put him down somewhere and ignore him. Let him come back to you if possible and repeat as needed.
If he continues then don't allow him on your hand. Use a piece of perch, cover your hands with gloves or a cloth. I spent some weeks in hat, scarf, gloves to stop Syd. He got the message and now rarely makes a mistake.
He isn't being vicious, it's a bit like a puppy that just doesn't understand how hard to bite, so you have to avoid giving him the chance until you both know the boundaries.
There are good threads and advice on here about bite training. Take a chance of reading everything you can find. It's invaluable. Good luck - but you won't need it. It will be fine.