i have a mobile oven and a pizzeria in ohio. we do most of our prep for the mobile out of the pizzeria. there have been times where we had a hard time handling dough for the restaurant and the mobile so i built a kitchen in my garage to handle the overflow.i applied for a home baking license from the Ohio dept of agriculture. it was 30.00 dollars and there requirements are a hand sink, ingredient label all product [ flour, water,salt, yeast],and no pets.
i think most states have this type of license available you may want to research it.