I got my boy Camo at 5 weeks old after he was abandoned at 1 week old. At 5 weeks I had him on taste of the wild grain free puppy kibble, softened with goat milk based puppy formula. Between 5 weeks and 8 weeks I weaned him off of the formula by gradually adding less fomula to the kibble. From 8 weeks on he has been quality kibble fed.
A year and a half later and he is very active and healthy.
Regarding hydration, let him have constant access to water during the day, taking him to pee often. Cut off water by 8pm at night to help with house breaking training.