Be warned: California is a ginormous state. The full-length PCH drive takes 12 hours at least.
Los Angeles area: So many cool places. Gotta check out Santa Monica, specifically the pier, Promenade, beach, walk along Palisades Park. Just gorgeous. Nothing better than watching a sunset from the fisherman's pier with shadows of Malibu cliffs in the background. Beverly Hills for the shopping and "I've been there" status. Westwood has a great nightlife scene as well as Diddy Riese and In-N-Out (and Pinkberry). Downtown LA has some nice spots, but also some not-so-nice spots. Chinatown is a blast though on the weekends. CBS Seafood has the best or second-best dim sum (depending on whom you ask) and isn't anywhere near as expensive as Empress Pavillion. Wanna see the first freeway of the West and third in the nation? Drive CA-110 from Pasadena into downtown LA. You'll go through such civil engineering marvels as the four Figueroa Street tunnels, pass through the LA Stack, and see the historic City Hall as you bound into downtown. Then there's the Getty. And Hollywood. Just so much in the LA area...The Grove also has the Abercrombie & Fitch flagship store, so you should enjoy it...it's 4 stories and huge, so let Chris know you're doing it so he can draw a map and write a story about it at your expense
Tips: get a convertible. you'll sit in some traffic, so get a tan while doing it. Plus when you're moving, the convertible rocks. Stay in downtown LA. You have excellent freeway access (110, 10, 101, 5) and almost everything is 20 minutes away.
South of LA: you cannot go wrong driving down into OC. Newport Beach, Huntington Beach, San Diego, Balboa, etc...so many beautiful beaches. Fashion Island in Newport is an excellent place to shop.
North of LA: It's a 6 hr drive up the Grapevine to the Bay Area. This drive is very boring, and it smells like aggriculture. The payoff is awesome though as SF is amazing. See the Haight Ashbury, ride the trollies, go to the best Chinatown in the USA...
San Diego: It's like a chill, warmer version of LA. Cleaner, smaller, more relaxed. Beautiful beaches. The zoo there is amazing.
Honestly you need multiple trips to see everything. It's just that intense. Have fun, though!