Statutes are laws passed by the legislature or by voters through the initiative process. California statutes are published in the California codes, available from:
Most statutes in California are passed by the state legislature, which provides many materials for free online:
Statutes may also be passed by California voters directly through ballot measures (measures on California election ballots.) Initiatives are measures proposing a new law; once on the ballot they are often called propositions. Referendums are measures to reject an existing law.
Many ballot measures are available for free online through the Secretary of State's office and the efforts of UC Hastings Law School. Other law schools and nonprofits provide additional text and commentary.