Samir is right. As your puppy is so small, it's very important to keep him under very close supervision. It's best to buy him a good cage and keep him under it when you can't keep him under supervison. Also, Like Samir said, don't expose him to the outside environment as right now he's immunity is low as he's not been vaccinated. After 3 month, you can take him for walks. Also contact a good vet who'll prepare a vaccination and deworming schedule for the puppy.