In order to be eligible to vote in the state of California, you must be:
- A citizen of the United States.
- A California resident.
- 18 years old or older on Election Day.
- Not currently in prison or on parole for a felony conviction. ...
- Not found to be mentally incompetent by a court.
Voter Registration in California | DMV.ORG
https://www.dmv.org/ca-california/voter-registration.php