The first thing to determine is whether to do indoor or outdoor food concessions. Logistically speaking, indoor concessions will generally be easier to organize and execute. If you have a place where you can use a commercial kitchen for free or for a small fee, you will not need to purchase or acquire much concession equipment. An easy and profitable possibility for a fundraising event is a pancake breakfast. Pancakes are an item that has very low food costs for large quantities and can be easily prepared.
There are some kitchen supplies that will be useful for making large batches of pancakes. The most important ones would be extra large stainless steel mixing bowls and large whisks for preparing the batter. For cooking the pancakes, electric or gas griddles would be a great piece of equipment to use as concessions equipment. While fry pans on a range can do the job, it is difficult and time-consuming to produce a lot of pancakes using this method. Griddles give you a large flat frying surface to cook many pancakes at once and are available in portable units. You can get griddles that run off of small gas tanks and are there before able to be moved to where they are needed. This is especially helpful if you do not have a kitchen to use as you can prep and cook where you set up your concessions table. If you choose to do concessions outdoors, there are many good options for that as well.
Offering outdoor food concessions can be more challenging than indoor but can also give you some great opportunities for fundraising. The biggest advantage of outdoor food concessions is that you can attend an event that is already planned instead of trying to bring people into an event you create. Talk to local fairs and festivals about running a food stand and many of them will be happy to help out an NPO. The ever-popular hamburgers and hot dogs are a simple and effective food item to offer at an outdoor event.
A vital piece of concessions equipment to have is a large charbroiler outdoor grill, sometimes referred to as a buffet or club grill. These will run on propane tanks just like the average home barbecue but provide a grilling surface that will allow you to cook a large quantity of hamburgers and hot dogs all at once. Regardless of whether you are doing indoor or outdoor food concessions, you should attempt to borrow or have donated as much concession equipment as possible. Ask local caterers or food service equipment companies if they will either let you use a piece of equipment or rent it at a discounted rate.