California Code, Government Code - GOV § 9023

At the day and hour appointed for the assembling of any regular session of the Legislature, the Chief Clerk of the Assembly, or in case of his absence or inability, the senior member elect present, shall take the chair, call the members elect to order, and call over the roll of counties in alphabetical order.  As the counties are called the members elect shall present their certificates, take the constitutional oath of office, and assume their seats.  If there is more than one senior member elect present and the senior members are unable to agree as to who shall call the session to order, the attorney general or one of his deputies shall call the session to order.

If a quorum is present, the Assembly shall then elect its officers, and there shall be no other business, motion or resolution considered before the election of the Speaker, save and except a motion to adjourn or a motion for a call of the house.