'Salright. It's empty, and really simple, but the colors are good, save for the text, which could use some work. That all said, it's better than most first sigs I've seen, mine included. I'd say go for it, you've got a knack already.
Erm... don't like the effects covering the render.
It has flow technically, but diagonal lines isn't usally how you do it...
It should also have lighting, and you should work on giving your sigs focal points (ie the area of the sig that your eye is drawn to)
Aside from those things, it's pretty good for a first sig since you're a beginner and all so keep improving. ;]