I have no issues going to game by myself.
I sat by myself for Jim Kellys last game vs Jacksonville next to a guy from Australia for his first game and didn't understand American football all. It was cool actually.
I have friends at tailgates so I would go there and have a few pops and good times. Sitting by myself is fun, I pay less and see the stadium from places I don't normally sit.
I will say this. If you know no one, go to Hammers Lot and introduce yourself to the Twobillsdrive tailgate and you instantly will have friends to party and hang with. Its starts early and you'll probably get fed too! Good people.