I'd also like to add...relax. You are expecting too much too soon from your lil' one.
Again, only a "harness" & never, never a collar for the risk of damage to your puppies neck & Collapsed Trachea. You are also trying to walk a puppy which is like expecting a toddler just learning to walk to endure a whole day at Disneyland on foot. Slow and easy...and don't forget the risk to your puppy before she is fully vaccinated and protected from the harm that could be out there on lawns, puddles, etc.
As for potty-training...this can take a LONG time with Yorkies as they can be stubborn but, for a puppy it's all new stuff to learn.
I would not allow your puppy to have full reign of the house and maybe cordone off a section with a x-pen that has piddle pads on one side and a bed and toys on the other...differentiating what goes where...lol
Anyway, I was going to suggest that immediately after feedings, you should make a routine of taking your puppy outside to potty. This is a great way to teach pooping outside.
Congrat's on your puppy!