Help with my puppy please!!!!!!?

ok my puppy is a teacup chihauaua (cant spell it) he isa almost two months old. his previous owners fed him purina antioxidents i havent heard of that. i know purina just not the antioxidents. what dog foos should i get him? they also said they mix hard and soft food for him but they didnt say what. so please give me some ideas on what kind of food to feed my new puppy please.