I hand feed my babies several times a day. Neither one of them are big eaters, and I am always scared they won't get enough if I don't prod them along to eat a little bit. I make a game out of it, and they gobble up many pieces of kibble. (Jett follows the leader with Bella, so itmakes it easier to get our little guy Jett to eat, wants to be like his big sister.)
If he is little he may not need more than 5-10 pieces a few times a day to fill that little belly. I free feed my two (keeping dog food out at all times) just because they don't eat much. He is probably eating more than you think
Good luck with your new little one!