URGENT HELP for Holiday Luncheon!

My boss is leaving for vacation and I am in charge of hosting the Holiday Luncheon for the company.

I need to know how many different type of dishes I need to feed 60-80 people from appetizers all the way to desserts so that I can see how much food will feed the employees. This will help me predict how many appetizers, entrees and desserts you may need.

PLEASE HELP! I have no experience on these sort of situations, I just got hired in August and this is my chance to prove myself. I'm freaking out!

Is this a potluck and you are tryi9ng to make a signup sheet? What are you responsible for? Meats, dishes, etc.? What is a closer count? If you plan for 60 and have 80, it is a disaster, if you plan for 80 and have 60, there are a lot of leftoveres. Is it for an hour at lunch or the end of a half day with people going home after. All these things affect planning. Take some deep breaths and write back with more info, please.