In the USA, to prepare food for commercial purposes, you generally need to have a kitchen that has been inspected and permitted for such things. You cannot, for example, use your own home kitchen (this varies by state, but that's generally true). Some states require training courses for all users of these kitchens (and some do not). Some require that the kitchen can only be used when someone trained is present.

I did not make anything up. The New Mexico law I mentioned went into effect only a few years ago. Before that, it would be illegal to, for example, bake a cake in your home kitchen and offer it for sale. This is no longer the case.