Need help picking out an outfit for a formal party?

Hi there, i'm about to go to a sweet sixteen soon and the birthday girl wants me to dress formally. It's just i'm quite indecisive. I need help picking out my outfit because i want to impress this girl. Can you help me pick out an outfit please? (ex. vest with pink tie witth black shirt and slacks. etc.) i can wear every color except purple. aha. i don't think it matches me. thanks!