For a large event, I would start by contacting a few caterers well in advance and explaining the expected guest count, venue, event date, and type of food you have in mind. Ask what is included in their package, such as staff, table service, equipment, setup, and cleanup. It is also worth checking whether they have handled events of a similar size. Before booking, compare the quotes carefully and make sure the final agreement clearly covers the menu, guest numbers, timings, and any additional charges.