I am in California, anyone can link or direct me in getting more info on getting the right permit if any on doing retail from a truck?

There are plenty of info for food trucks, a little confuse of just doing retail, selling stuff from a truck.

Trying to see if there are special requirements for mobile retail, where we would go to certain areas, park on the street and setup for retail for a few hours and move on. We already have a retail location and trying to move around where some of our customers are located for a few special event.