Great news! For the first vet visit make sure you bring any records from the breeder or previous vet like vaccine information. Ask your vet to give you some pointers on common chihuahua problems like soft spots, knees, low blood sugar, and reverse sneezing. As far as introducing your pup, take a look at the stickied post by luvmypuppet.
Good luck and post pics!
Good luck and post pics!