One piece of advice, and I don't want to come off across as rude but it has to be said, don't be an idiot. You're a guest in another team/fan base's home; act as such. Applaud and root for your team, but don't take it too far (the biggest mistake visiting fans make and pay for.) I've been to Yankee - Sox games in both Fenway and Yankee Stadium, and this little bit of advice has served me well.