Get there 4 hours before the game. Park on one of the lawns across the street from Hammer Lot. There’s plenty to do and see around the stadium. I would suggest lining up at the gates 15 minutes before they open, you’ll be able to get in and see the players warm up. If you wait til 12 to get in you could miss part of the game. If you’re on the tunnel side you’ll get to see a lot of the Bills players. Diggs throws the ball around with fans.
My wife only ever liked the Yankees. She made fun of me for being a bills fan and liking football. She never understood why Western New York was obsessed with football and didn’t understand my fandemonium I took her to the Tennessee game. We sat in the 2nd row, got on TV, saw Bruce and Thurman up close, caught a football from a titans player and the bills won. Now she’s a bigger fan than I am.