If you go to Newport Beach, stop by Balboa Island and get a frozen banana (sadly, the stand isn't shaped like a giant banana):
http://www.yelp.ca/biz/sugar-n-spice-newport-beach-2
If you like roller coasters, Magic Mountain and Knott's Berry Farm have some good ones. If you don't like coasters, I wouldn't go to either park.
For Disneyland, go in the middle of the week to do the rides. Learn how to use the FastPass system. If you want to see the fireworks and Fantasmic, you may have to go on the weekend during the fall, so consider spending at least 3 days to see everything between the two parks.
If you want to see the "Hollywood" stuff. You can go to the Hollywood & Highland complex, which is where the Chinese Theatre (with the hand and foot prints) and the Dolby (formerly Kodak) Theatre (home of the Oscars) are. Jimmy Kimmel tapes his show across the street from Hollywood & Highland every weekday night.
If you want to go to a movie studio, Universal is a working Studio, but it's really more of a theme park with a tram tour around the backlot. Warner Bros has a much better Studio Tour if you want to see actual sets up close (and even walk around on them).