Order a ton of pizza. Maybe 9 for 30 people? Meat, veggie, cheese, and a white or two?
Have a big giant bowl of lettuce and a big giant tray of salad fixings (veggies - fresh and marinated, olives, meats and cheeses if you're feeling fancy, hot peppers) and about 5 types of bottled dressing.
Buy cupcakes and cookies or candy.
Paper plates and napkins, plastic silverware.
Done!