Legal Question in Landlord & Tenant Law in California

In California, a minor cannot make a contract relating to real property or any interest therein, which would seem to include a lease. So, yes, it probably is not valid and you could probably disaffirm it (legally break the contract). However, to disaffirm a non-real estate contract (not relating to real property) the rule is that that has to done before the age of 18 or within a reasonable time afterward. I'm not certain if that rule would still apply to your lease. That would depend on the court deciding if the landlord takes you to court.

https://www.lawguru.com/cgi/bbs/attyPages/liem.html

Note: The above response is provided for legal information only and should not be construed as legal advice, nor to create an attorney-client relationship, which can only be established through payment of consideration. We do not offer free advice except for the information provided herein on LawGuru which has been screened. If follow-up advice on your specific situation is desired, we offer a paid consultation in person if you are in the Los Angeles area, or by phone or email.