Get tickets to see a game at War Memorial Stadium. If there's nothing on while you're in the area, you might like to check if they offer a guided tour of the facilities.
You're spoiled for sightseeing choice when visiting Buffalo. War Memorial Stadium is an ideal place to begin here, but there are lots of other worthwhile attractions to experience. KeyBank Center, Buffalo Zoo, and Sahlen Field are not far from the sporting facility and will round out your day nicely.