Guess what? A big football game is happening this Sunday. (It’s being aired on CBS, CNET’s parent company.) It’s the 50th Super Bowl, the final game in the NFL season that determines who wins the shiny Lombardi trophy. It’s about four hours long, it has a long halftime show, and everyone you know will be talking about it on everything.Let’s assume you know how football works, just a bit. Hopefully. If not, at least you can follow along with a few of these points and notes, just to catch up on what this year’s game is all about. If nothing else, consider this your crib sheet between appetizers.1. It’s the old “young guy prodigy vs. fabled old guy” gameThis year’s game has the greatest age gap between QBs in a Super Bowl ever…13 years. Peyton Manning, the Broncos quarterback, is 39…the oldest starting QB in Super Bowl history. Cam Newton, the Carolina Panthers’ quarterback is 26. There’s the span of a bar mitzvah between them. It’s the Millennials vs. old guard, or whatever you want to make of it. The Super Bowl’s had a lot of these matchups: Kurt Warner vs. Ben Roethlisberger. Tom Brady vs. Russell Wilson. Russell Wilson…