my first was playing a few covers with my guitar/bass teacher and his mate who play together all the time.
They'd been booked to play a wedding and decided i was ready to play with them. i was about 16 at the time so i was crapping it!
on the night i asked "do you mind if i kinda stand at the side of the stage? i'm dead nervous" and they both reply "sure!"
so the time comes, i'm invited up to start playing midway through their set, to find i nice wee clearing has been made for me...slap bang in the middle of the stage! my teacher (and singer) likes to stand stage left, and the other guitarist stage right, so i'm given the frontman position in front of a PACKED town hall
the songs went alright though and i didn't mess up, quite sadly it's still the biggest gig i've done