I suggest dividing your trip into two parts: southern california and northern california. In southern california, stay at a hotel in or around L.A. and go to Disneyland, movie studio tours, and at least one beach town ( I recommend Laguna Beach). You could also stop by San Diego for a couple of days. Then, head up to Northern california and spend some time in San Francisco, Yosemite, and Napa if you are into wine. Be sure to visit a beach town or two (Monterey, Carmel, Santa Cruz, and Big Sur are all good choices). In norcal you will have to stay at a different hotel for each destination. Do some research to figure out which places in california interest you the most, and remember that it is practically impossible to see everything in one trip- but you will still have tons of fun!