Here are some links to places you can search on the AKC website.
American Kennel Club - Club Search and Directory American Kennel Club - Club Search and Directory
The first one is for conformation clubs and the second link is for obedience clubs. There is also some other info on that site that might help you.
Yorkshire Terrier Club of America
The Yorkshire Terrier Club of America also has helpful info. None of this is a guarantee of anything. You can talk to the club people who may give you names of breeders they know of. You can go to shows. It is best to research the breed and the breeders and be very sure of who you are dealing with and that a Yorkie is really what you want for a pet. They are terriers and have some terrier traits. While many people love them they are not for everyone.