The first single I owned was Cliff Richard's "Please Don't Tease". My cousin gave it to me because she didn't want it, and I was thrilled to bits (well come on, I was only 12 or 13 at the time).

The first one I actually bought was "Blue Moon" by the Marcels. I found a second-hand shop that sold singles at a price just about affordable on a pocket-money budget, and that was the first one I found there that I liked.