How to handle issues with a large puppy I'm sitting?

I am currently house sitting for a very large 1 1/2 year lab. The dog is still in his puppy stages and likes to play very aggressively and has bitten a lot while playing which do hurt. Also, he is very strong and hard to control on walks to the point that he almost pulls me down and makes me fall since he pulls very hard and fast when excited. Any ideas for how to handle this type of situation? I feel as I'm almost not equipped to handle his behavior and have sat for other large dogs but never came across this issue before?