What is the weather like in California? And what kind of clothes should I bring?

Leave the shorts at home. At this time of year in Calif. capris and jeans are better and more comfortable. Northern Calif. will be about 60 - 70 ish and cooler in the evening so a sweater and a all weather jacket would be good. It may rain. Things to do there are more casual so don't know where you plan to wear a dress or a skirt when traveling there. Even if you go to a very fancy place for dinner, slacks or capris with a dressy top would be suitable.