I never danced as a teenager; I felt incredibly awkward. In 1990 I started contra-dancing and English Country dancing, and I fell in love.
If you've never experienced the exciting-yet-wholesome feel of a good community contra-dance, you owe it to yourself to give it a try. Contact the Country Dance & Song Society and find the dance group nearest you. As one wit put it, "It's the most fun you can have standing up!"
There's a lot of good contra-, English, and other folk dancing in southeastern Michigan. See the AACTMAD Home Page and calendar page for details. AACTMAD also sponsored an informal singing group, and I have archived some miscellaneous songs that we sang.
I occasionally call English and contra-dances; see my collection of dance cards. CDNY also has a nice collection of dances on-line.
Because I often travel to Washington D.C., here's the Folklore Society of Greater Washington page, which has some good dance information. Also see the Folkal Point, a good folk music coffee house.