Obviously its pretty basic but for a first signature I think it turned out pretty well. Keep making them and hone your skills and you'll improve, there are plenty of graphics resources out there =]
Pretty decent first attempt, beats my first graphic Let me just point out some issues I'm having with it, just for your sake, so you can improve it. There is a pixel on the loose above the 'E'. The ghost is semi-transparant. In this sig it would be nicer to have the ghost solid white. The ghost's edges are very sharp, look at the white pixels surrounding the black outline. The ghost also seems like it was not your drawing, copy-pasted if not heavily inspired. The pumpkin dito, seems like it's not your own. Try and make all the elements yourself, or heavily modify each one so they are your own creation. That would be the best way to start out in this business.
Well, it's quite basic, but it's okay for a first time. You should probably search on google for tutorials