Need ID for registration and/or the first time voting.

https://www.sos.ca.gov/elections/voting-resources/voting-california/what-bring

However, if you are voting for the first time after registering to vote by mail and did not provide your driver license number, California identification number or the last four digits of your social security number on your registration form, you may be asked to show a form of identification when you go to the polls. 

https://registertovote.ca.gov/?

What You Will Need

To register online you will need

• Your California driver license or California identification card number,
• The last four digits of your social security number and
• Your date of birth.