You answered your own question! I concur with taking him to the vet just for a check up. As for the fall, if you are providing correct husbandry it
shouldnt be anything serious. You just got him, if hes a juvenile i wouldnt think MBD or anything like that. But yes fecals for parasites is a great idea!! A cup is also a very small and weird surface for the chameleon to navigate, im not sure why he was on a cup but there is nothing for him to grasp on, so he may have just slipped off.
Hes a new cham, he is probably pretty stressed. How often are you handling your cham? And does he come to you when you out your hand out or are you grabbing him from the enclosure to handle? My best advice is to leave him alone in his enclosure for a couple weeks. My cham was very stressed after the move and it took months before i was even able to get near him without him hiding from me. Just takes a little patience.
@Beman has a great blog on here about handling and building trust with your chameleons. Def worth a read!