My daughter is a caterer and here in Canada you would be shut down instantly if you did as you plan. Anyone handling food NEEDS to have a Food Safe certificate - that's just for starters. Food needs to be prepared in an inspected and approved kitchen.
When I helped serve with the Lioness (womens group of the Lions Club) for their annual fundraiser at a holiday event, they made sure we had these certificates and a license and our grill was inspected, etc. Those who sell at farmers markets are also inspected.