not bad for just beginning at all... like the sparkles.
Usually when you start with the sig you try to take colors from the render itself to use in the background, especially abstract ones like the one you made. So the colors that would go good with her are red and white, with maybe some black in it.
So start trying to incorporate the colors from the render into the Background itself. This makes it blend better and overall mesh the sig.
Let me give you a tutorial, that I learned a lot from. It tells you basic rules(more guidelines) of sig art. It is very good. Be sure to check out the color wheel on it.