Since we're talking firsts... my first was a Honda Dream 150. Looked like a tank; I think it was before Honda learned to creatively bend sheet metal.
I moved up as soon as I could afford it: a Honda 350 CB. My first "big iron" was a 1969 Triumph Bonneville. I taught my then girlfriend (now wife) how to ride on that bike. Some things haven't changed so much in all these years... I think I hooked her because I had long hair, played guitar in a band, and rode a motorcycle... the parental "trifecta nightmare"!!
Well, I'm a one-man band these days, the hair is lots shorter and thinner, but I still ride. Still with the same Blonde. And it only took her Mother about 35 years to warm up to me.
Captain Jim