Our family loves attending Iowa Hawkeyes games at least once a year. The football stadium is absolutely wonderful about allowing us to carry in GF snacks for our celiac kids. At the door, they place a medical tag on our bag and no one questions it. You might say it’s one of the perks of celiac disease (if you can call it that!).
Some places are not as celiac friendly. Call in advance to see if they allow food or drink to be carried in. Let them know your diagnosis as there may be exceptions. You may need a note from your doctor confirming your diagnosis. It is always a good idea to have one with you. If allowed, take an easy to carry cooler bag or backpack cooler with GF drinks and snacks. These portable coolers are a life-saver.
Chances are there will not be many GF options available at the concessions, so you will be happy you packed some snacks (so will the kids!). You can ask if GF options are available at the concessions, but it is far more affordable and usually safer to pack for yourself. If you are not allowed to take food in, fill your bellies before the event and plan on having a cooler packed in the car for later - or find a safe place to dine out after the game with the findmeglutenfree app- it's a free and amazing resource!