During this 24 years I have had hamsters, I have noticed that hamsters from pet stores can take up to 3 to 6 months to get tamed. Not all but sadly most of them. While the once you buy from a breeder is normally tame when you get them.
They often freeze when they listen to sudden noises, even those that a human ear has hard to pick up...
When he freeze just talk with him with a calm loving voice and he will start to move again after a short while. My hamsters can freeze when they hear me come up the stairs...I then talk with them with a loving calm voice and they start to move around again entertaining themselves.
When taming a new hamster, patience is required. Giving him treats daily from your hand is good, so that he gets used with you smell. When you start to train him to bee used to bee picked up, and you are scared that he might bite you, use leather gloves till he gets more used to being picked up, cuddled and handled. When he is more relaxed with you, you can stop using the gloves.
It takes time to tame hamsters and patience and daily work of taming the hamster is needed. Good luck!