Welcome to YT.
There are some very cruel people in this world, I will never know how anyone could treat any animal like that never mind a puppy.
But you have her now and she is safe, thank you for saving her and giving her another chance at happiness.
It sounds like you are taking good care of her and she has everything she could ever dream of
I would give her a few more days to get settled in your home and then introduce potty training.
How old is she? and do you know if she has had all of her injections?
Untill you find out I would train her on pee pads, good luck!