I was just wondering what is needed to start a cake decorating business in CA. Where can I find the information (such as licensing, commercial kitchens, etc) needed to get started? If there is anyone out there who can help me I would really appreciate it.

In California, it is not legal to bake and sell from home. In many communities, you cannot even build a commercial kitchen.

Your local health department is the best place to start. You can look around for kitchen space to rent. you need space to store your goods since all baking and decorating must be done in the licensed space.