As with all newborn babies, they should not be on a solid diet, they have to ingest mothers' milk to develop properly and healthy. There are formulas made for pups in the more popular stores, as well as bottles to feed them from.
Puppy should be fed milk until it is about 6 weeks old, and then you can start adding the solids slowly, in this transition, the bowel movements will begin to change, and look different, so don't panic when they do change. Hope this helps, good luck.