If your domicile was in CA all of 2020, and all your income was earned in CA, then you file as a full-year resident of CA.
You find CA's definition of "domicile" on page 10 of this reference:
https://www.ftb.ca.gov/forms/2020/2020-1031-publication.pdf
Your residency for tax purposes is determined by where you actually live, not by your mailing address.
**Answers are correct to the best of my ability but do not constitute tax or legal advice.
