California is huge OP and if you want to start in LA the first thing to decide is how many days do you want to spend there? LA is big and there's a lot to do, depending on your interests. Some people hate it, because it's quite dirty and there are lots of homeless people, many of whom are obviously on substances or have mental health issues. They are camped out or lying on the streets of many areas of town inc. Hollywood and all along the beach areas.
So what do you want to do in LA? Do you want to do Disney (2 parks = 2 days), Universal Studios, Warner Bros Studios, Paramount Studios? I wouldn't recommend doing all of the studio tours unless you're all huge film/TV fans - I'd pick one. Do you want to do Hollywood, a minibus tour of stars homes (which is kitsch and fun), Griffith Observatory (great at night to see the lights of LA), Santa Monica, bike ride along the beach to Pacific Palisades, Venice, the La Brea Tar Pits, the Petersen Car Museum, the Academy Museum of Motion Pictures, Rodeo Drive, hit the malls? If you want do all those I'd recommend 5-7 days in total.
Then either head north (Malibu, the Pacific Coast Highway, Monterey, San Francisco), or south through Orange County, have a couple of days in one of the nice beach towns en route and end up in San Diego, which is a lovely city with, again, loads to see and do. You can drive back to LAX from SD in 2-3 hours.
But basically, two weeks you can't do everything so pick your priorities, build in some downtime and don't try to do too much or you'll spend your entire time sitting in the car looking out of the window.