I am going to a local ballroom dance this month.. I think it will mostly be older people. I have never done this before. My husband and I are 20 years old and we have no clue what to wear!

Does he wear a suit?? or just a nice shirt??
dress pants?? nice shoes??

Do I wear a dress and heels?? dress and flats??
Nice pants amp; nice shirt??

I have NO idea. Dont want to look too over the top if everyone is casual. But If theyre dressing up nice, i want to look nice too.