You are getting certified in a fantastic place to be a diver. There is so much to explore in Southern California!
My words of wisdom: Do not think that your OW class has taught you everything there is to know about diving, or perhaps not even all the things you need to know as an OW diver. Stay curious -- read threads here, and perhaps on other boards, and ask questions. If you are a reader, pick up the PADI Encyclopedia of Recreational Diving and go through it. There is a lot of good information there, beyond what you will get in your basic class.
Reach out to more experienced divers as buddies. You can learn a ton, especially about how to handle local sites and conditions. Many divers don't mind diving with newbies at all -- we thrive on their enthusiasm.
Educate yourself about the sea life where you dive. It makes dives much more interesting.
Don't rush into buying equipment. You may very well change your mind about what really works. It's a lot less expensive to buy the right stuff the first time.
Work on your fitness. Surf entries and exits are easier if you are quick and strong (I'm neither)!
Come back and tell us about your class, and your adventures diving.