It is so nice if you will visit in Orange County and Los Angeles County areas. Disneyland Park,Universal Studios, Sea World are some of the awesome places to see, Laguna Beach and Huntington Beach are good places to swim and surf and for sure you will have fun. Don't be scared of earthquake, it does not really happen often. If you're coming from foreign countries, you can get a tourist visa from any US Embassy located in your place. Californians are very nice people.. Enjoy your vacation.

Do you advise me to spend the holiday in California

ok a live in souther california and i recomend you universal city work walk of famr in los angeles , and couse i live 5 minuts of disneyland check th park out. hope you enjoy come here , nd have fun

I am planning to visit California in next Sept what is your recommendation about interesting thing to do there, did I need to rent a car or no?