Welcome to cruisereviews.com! From the information you provided, it appears you're traveling on Carnival? If so, Carnival recommends no earlier than 12:30 pm for flights out of LAX and no earlier than 1:30 out of Orange County. This is buried on their Web site HERE.
(If the link doesn't take you directly there, go to "Before Your Cruise" and scroll down.)
From personal experience, I'd leave at least another hour as LAX especially can be crowded on cruise debarkation days.