Only buy quality animal food from a pet food store (or Costco) never from a grocery store. With so many great pet stores offering a wide variety of top quality food, it's really your choice, and what you new animal will eat. Sometimes in the beginning it might be trial and error so perhaps small bags to start with until your find the right one. Some good brands include Zignature, Merrick, Wellness, Royal Canine, Taste of The Wild and Kirkland brand from Costco.
We may not be able to narrow down what quality food is best for your new animal but we can certainly tell you what foods NOT TO FEED a animal. Do not feed any brands available in a grocery store (Purina, Pedigree, Beniful etc.) These low-grade foods are over processed, filled with fillers like corn, preservatives and toxins which are very problematic for animals. Also, no products at all from CHINA.