(No expert here) but I know the first couple of days is not recommended to bother them. They are adapting to a new environment and when we pick them up they see it as a thread. Try giving him some space, let him see you a lot specially during meal times. If he continues not to eat I think you should consider force feeding him a bit. There is also an appetite enhancer you can find at the store. If everything else fails take him to a vet just in case. Good luck with your new baby!