Well first off, welcome to YT! Yorkies are a wonderful breed, who are very loving and fun spirited. A pleasure to have, and how lucky of you to find one for FREE!! When would you be getting the pup? 5 weeks is very young, and they actually suggest not adopting a yorkie until they are 12 weeks old due to the small size of the breed. This is also because many of the genetic problems in some yorkies cannot be detected until this age. ANyhow, back to your questions. Yorkies can be difficult to potty train, and it does take a lot of commitment and consistency. And, even after your yorkie is potty trained, you will likely still have accidents. You might have problems trying to seperate time between pets as yorkies love to be with you all of the time. They are very people oriented and just love being near their person. However, overall a yorkie is a wonderful companion, and in my opinion if any dog can make you melt it would be a yorkie. They just have a way with their little kisses and their sweet little faces.
Good luck!