I brought my girl to the vet within the first week or two of owning her. I did this for several reasons: I was a new chin owner and wanted to make sure I knew what was normal, I had some questions that I wanted to ask the vet, I wanted to establish a doctor-client relationship for future reference and a huge reason I went was because I had a coupon for a free first exam (VCA website has them pretty often). That being said, Chloe was pretty stressed and like Peggy said, there's not a lot that the vet can actually do during a superficial exam. If you definitely know how a chin should look/act etc, then there is really no medical reason to get them checked out.
If you want to meet a vet and find out if you like them that's a whole nother story. I kind of look for vets the way an employer interviews a job applicant. I want to meet them, ask them questions, see their hospital etc. Of course, if you already know a vet or have a trusted source that reccomends them then you probably don't need to do what I did.