Hi joanna, i got my yorkie when he was 5 months old and i was also a little worried that he may be to old to start training and could possibly not warm up to us because he was already used to another family, but he has turned out to be a great dog and adjusted very fast.he is 9 months old now,and weighs in at 2.6 lbs.(he was 1.1 when we got him at 5 months)we feed him innova, you really have to study and find the proper food for your pup. And as far as potty training
go ahead and program the carpet cleaning company in your phone, because yorkies are known to be one of the most difficult dogs to train) ( but worth every accident) and we use paul mitchell shampoo for dogs it smells really good and leaves him soft and shiney(we keep a puppycut on him) hope this helps, and just remember any bad day turns into a good day when you look at that cute little face.