I'm sure you can teach it, quite a few people here have taught their dogs to hold a treat on their nose (Nebo, Bob, Simba...etc).One of them (Simba) will even hold steak in his mouth until he's told it's ok to eat it
And no he's not too young, start training now!! The younger the better
We started with my girl Roxey when she was 8 wks old, she didn't always listen or like what we were doing, but she eventually understood that she had to do it.