IDK...I went into Petco the other day to pick something up-on a Saturday- they were holding the training in the middle of the store (OK for more advanced) people were stopping and distracting them-and the 'trainers' were basically screeching 'No!' everytime the poor puppies got sidelined by a kid with a lollipop...
On Long Island- we have a great local trainer who's been in business for over 20 years- we took our first Yorkie to her class and really learned a lot- especially with this breed...they can be really manipulative-
Do a little research for a local trainer- this woman is about 30 bucks more than Petco- well worth it, IMHO-