Most homecomings have a formal dress code for guys and you can wear a tux. If this is not possible, you can wear a nice pair of pants and a suit jacket and match your shirt with what your date will wear. For girls the dress code is pretty much a dress that stands out. You can have a print or trim dress or an off-the-shoulder dress with a beaded trim or rhinestone trim. You can have just a suit instead of a tux which would also work out well.
Lucky, well if it's the classic one then it's an 80's style, which means those weird frilly shirted tuxes if its formal, try watching the movie if its not formal but it most Likely is if your a girl then not much would have changed, but the dress and skirt length would be longer.