Just saw this...
Everyone gave you great advice.
Here's a little rundown of what CA and most Counties require under Bill SB 946:
1. Permit to operate.
This will only be issued if you can show proof of a health department inspection, a fire marshall's inspection certificate and a Commissary Kitchen Agreement, a form of legal entity, such as sole proprietorship, LLC, S Corp and a valid business license.
A fictitious name, DBA as....
Insurance: Liability & regular
2. Food Manager's License.
As an Owner, you'll need a Food Manager's Certificate, not to be confused with the Food Handlers license!
4. Plans
Take measurements of your proposed operation, whether it's a pizza cart, a tent, a truck or whatever you want.
You need to provide a detailed plan of your operation. That includes drawings of the size of the tent/cart/truck or whatever you plan on using, to scale of course.
It'll include a required list of sanitation devices, such as a portable hand washing station, towels, soap, as well as items that hold foods at the required temperature, such as meats & cheese.
5. Electricity
You need to power your operation, right!?
A quiet, portable generator will be just fine, depending on the wattage your equipment uses. So check first!
Battery packs and 12Vs won't last long.
6. Prep tables
You might get away with foldable prep tables but the Health department might feel different about it. Be on the safe side and order some food safe stainless steel folding tables of off webrestaurant. Saves a lot of hassle.
7. Insurance
Gotta have it. No insurance, no slinging pies.
There are several lower cost options available but definitely shop around.
8. Holding equipment
The Health department wants to see that you're capable, or your equipment that is, of holding foods at their required temperature for your stated hours of operation.
Which means, that you either need a commercial prep rail connected to a generator, or something that can keep toppings cool with ice packs. Ice packs are no guarantee, though.
I'd personally go the route of generator and cooled unit, rather than depend on ice packs.
Although, Refreeze ice packs are exceptional!
Anyway, that's all I have for now.
I wish you well.