The water temp off Huntington is 62 to 63 degrees. Still able to surf with a spring suit, but not for very long. If you want to snorkle or dive, Laguna Beach has some nice coves, although water clarity is not good since we had some heavy rains. As was mentioned, Catalina is great in the kelp beds. Lots of Garibaldi, some yellowtail, stuff like that. Nothing you can catch to take home for your tank though.
If you go thru Long Beach check out the Aquarium of the Pacific, good representation of the types of fish you would find around here.
To answer your Newport question, it is in Orange County about 45 to 50 miles south of Los Angeles. Beautiful area all around here, especially of you go do some boating!
Welcome to SoCal, hope you enjoy your stay!