If you have breeded them yourself then you will have to wait about 4 weeks after they are born bt if you have just bought one then i'd start holding it the day after you bring it home
You certainly don't want them to be eaten by the mother or father hamster, which can and does happen. So you need to take some action, or rather inaction to prevent this. I say inaction because the...
You just need to train him. Robos are very wild so it may take a while to get him tame. My robos had babies and I trained the babies from birth so they were a little more calm.