^ You have to play a legacy AFL game. That occurs only when 2 original AFL teams play together. So in week 1, there is the Bills vs. Pats. That is a legacy game so play that one and you will get the achievement. The AFL presentation will turn on automatically for a legacy AFL game in franchise.
Is there a little AFL symbol when you attempt to play the game. They only have a few legacy AFL games per season. Not every matchup between two AFL teams is considered a legacy game. Just follow my recommendation. Start a new franchise as either the Bills or Pats. They play week 1 and I can guarantee it will give you the achievement because it gave it to me.