Here is how you can register to vote today:
Go online by using the California Online Voter Registration System at /registertovote.ca.gov/
Call (800) 481-VOTE, (800) 815-2666 Option 2.
In person at a Los Angeles County government building (Call first to confirm if open)
Mail a completed voter registration form, which can be obtained by picking up a voter registration form at most government buildings.
If you miss the deadline, conditionally register and vote at any vote center location in Los Angeles County. Many open on October 24th.