What to wear to date?

Me and my boyfriend are going on a little date tonight. Were going to a roller derby game. Its inside. What should I wear? and how should I do my hair and stuff? Roller derby is where you dress all crazy and stuff and everyone is rough. But I dont want to dress crazy cause Im not on the team but I also want to look good there and not really girly. The weather is 57 out today too. Were leaving at 6. What should i wear and how should I do my makeup and hair and stuff?