Potty issues are also dependent upon whether or not he was totally housebroken in his previous home. Also, has he been neutered? Does he mark?
As far as food, the question would be what his diet consisted of in his previous home?
Is he a rescue or are you adopting him from a family who is rehoming him?
I almost forgot, but do you know if Biscuit has ever been around cats in the past? Some people have had their yorkie's eyes scratched, so that is a situation that needs to be closely monitored. Also, the litter box may need to be moved where Biscuit can't get to it. Some yorkies snack on the contents and become ill.
Last, welcome to YT and congratulations on your new yorkie. Biscuit is a cute name, too.
