Hi Guest
Your breeder should give you a diet sheet or information for when you first take your pup home. Ring then and find out what they are feeding so you can get some in - is is best to keep a puppy on the same diet and regime for at least two weeks to cut down on the risk of stomach upsets. Everything changes when you take a pup home, people, environment, water so if you can keep at least one thing constant it should help.
You may find your pup goes off its food for a few days to start with, don't worry as this is quite normal.
You will also find there are as many opinions on feeding dogs (almost) as there are people on this board :)
Christine