If you have carpet and your afraid of accidents in the house, a hand held carpet cleaner (30.00 at walmart or target) are great and quick, even kids can help, so even if there is an accident your carpet doesn't get stained *just clean and empty it frequently or it smells*
I do agree if you haven't paid for it yet, back out, pet store puppies can have many more issues because they aren't coming from a reliable source. Obviously not to sound mean, but your children and you will become attatched. If you are doing this I wish you the best of luck, be patient with 'cody' if you get overwhelmed dont' be afraid to come here and ask for help.
As for the food, I am NOT a fan of science diet, every dog likes differant things, but i would say get a food for small puppies, but SLOWLY mix it in with the science diet to transition him.
Get some puppy toys for him and thing to chew. Get a book about training yorkies, my husband and I got the complete idiots guide to yorkies and it helped us tons with our first one!
Good Luck!
