It's a good idea before starting your business to check with your local authorities about laws and regulations, licensing, etc. There were a couple of young boys who got into trouble for selling cupcakes without a permit. Here is the news story: Cops Called on 13-year-olds for Selling Cupcakes.
Talk to an adult about what you need to do to comply with laws and regulations. Ask a parent, teacher, or business leader in the community. You don't want your business to get off on the wrong track.