I never took ap bio and ap chem before, would that be a problem if I want to apple to UC davis for nutrition major?
You do not need to take an AP Biology or AP Chem course to apply to any UC, but having the background in these classes would be beneficial since the Nutrition Science and Clinical Nutrition majors require 3 quarters General Chem, 3 quarters Biology and 2 quarters in Organic Chemistry as part of their major requirements at UC Davis specifically.
An Honors and even Regular course in both subjects would be still be better than none at all.