I first sang in front of an audience when I joined Jr. High chorus class lo these many moons past ;D

The first time professionally was a lot later. I was all of about 22 or 23, and I sang madrigals at a festival. We got paid nada, really, but it was my first job singing under contract.

Now, it's mostly folk music at festivals, coffee houses, parties, bars, and the like, and for a much better rate of pay.