If you don't have significant assets, children, or dependents with special needs, a simple will may work for you.
Laws in California – Prob. §§6100
Witness Needed in California – [...] the will shall be witnessed by being signed, during the testator's lifetime, by at least two persons each of whom being present at the same time, witnessed either the signing of the will or the testator's acknowledgment of the signature or of the will and understand that the instrument they sign is the testator's will.