Have you tried looking on the YTCA website? They have a breeder list there for different states. You may be able to find a breeder that is willing to mentor you. Just a thought. Also, some of the best breeders on YT suggested to me that I start going to shows and get to know the breeders there. Maybe, you can find a great mentor there. I will be attending my first show next month and I am very hopeful that I will meet some wonderful people.
Here is the link. Good luck to you.
Yorkshire Terrier Club of America About The Club 
YorkieProud