Do I need to make products to keep guests happy?
No, you don't need to make products to keep guests happy. Guests will use your businesses to fulfill their needs e.g. if they are hungry they will look for a nearby restaurant. If your guests are unhappy, see this page for info on what to do.
Making products is an additional feature of businesses that allows you to make extra products that are required by certain goals or required to run events in activities.