Cold @ night & morning

Google your questions, you will find all your answers.  And also find coupons to theme parks, stores, restaurants.  Don't believe everything on Yelp.  But if the place has so many reviews then you can trust. 
In CA is always cold at night and early morning.  You do need a warm jacket if you come in winter.  Sweater or long sleeve shirt is good during the day.  Here in CA people even wears T-shrit and shorts in winter.  Wear a long colorful scarf.  It will keep you warm and also you will look pretty in pictures. 
I think you should buy makeups in the mall, such as Macy's, Nordstrom, prices will be the same no matter where you go.  But if you buy from the department stores, sometimes they have promotions you will receive free samples, and they usually worth to have.  South Coast Plaza is a good place to shop, also Fashion Island in Newport Beach.  You can do shopping, dinning, and also sight seeing at the same time if you go to Fashion Island.  It's close to the beach.  It's very pretty there.
Welcome to CA!