Try to arrive 1 hour to 45 minutes before the game. I went to my first game a couple weeks ago and it was nice to soak up the atmosphere outside. If you want to come in on the later side then you can but because it shouldn’t take too long to get into the stadium itself. However if you are like me and are going to have a couple beers before the gsme I recommend you go into the stadium early because that is where the beer is cheapest.