Also be aware of a few essentials;
you need liability insurance if you are providing food in case a guest or staff is sick or injured. You can be sued.
In most states it is illegal to prepare food in a home kitchen for sale. You can do it at the host's house or in a licensed kitchen such as a church, school, or restaurant.
Food is usually 1/4 to 1/3 the billing for caterering, depending on the arrangements (full service, drop off, etc.)