Food and food handling varies by state and by meal. You will need to check with your state or county health department to see what you can and can't do when it comes to serving food to your farm stay guests.
Some farms cook meals; others are self-service, which may mean they provide a stocked kitchen but not the cooking, or all they provide are the facilities. There are states that allow for the cooking of breakfast but no other meals without a food license (i.e. California); others do not.
Do you like to cook? Do you want to share meals with guests? Or, do you think your guests will be happier with their own meals and their own schedules? In Italy, the food is a large part of the experience. But, that's not to say a guest with access to what you grow and eggs collected from the coop won't be just as happy.
University of Vermont, on its website Vermont Agritourism, has pulled together a several articles about food safety on the farm, to include u-pick and farm stands, but nothing specific to farm stays. Still, the information is important and useful so we are including here:
University of Vermont: Food Safety and Good Agricultural Practices
Rutgers University: Food Safety Checklist