Food

Hi ! I'm Saphyre 3 months old. I'd like to know about NATURAL CHOICE food for adults. When should I start this type of food. At present I eat 2 cups a day of food for puppies.
This p.m. I'm gonna receive my 2nd vaccination. Will I have a reaction ?
I'm very insecure when my master leaves me alone so I bark constantly until she comes back.
Any suggestions ?