Everybody's first MOCs are great! I love seeing this.
I looked through my stuff, and although some of the first MOCs that I remember making were around 1986, I don't have any pictures of these, at least digitally. I'll have to really dig through negatives to see if I can find a copy. I'll post if I can find them.
This is a picture of a castle that I started in 1990, but later abandoned. It was never finished, but is probably the first MOC that I have a digital picture of. Pardon all the junk and extra pieces in the middle of the castle. It was a work in progress.http://imgur.com/v1okqWe