If you want to see them enter the field before the game, then all you have to do is get to your seats about 5 minutes before kickoff. If you want to see the Hawks go through game day warm-ups & drills you need to be in your seats about an hour before game time. Remember the Hawks go back into the locker room about twenty minutes before kickoff for last minute instructions, pep talks, etc.
Now if you want to see the Hawks enter the locker room, then you have to be outside the stadium about two hours before kickoff.
From your question, I really don't understand what you want to do.