Not bad for a first signature.
And of course, its not that great.
She looks like she's been slapped on a black and white background an a... those thing at the right side of her.
Work on your blending.
Beginners seem to like the Bevel and Emboss feature, try to avoid that.
Some lighting would be nice.
Add depth.
Other than that, if that's how you wanted it to be done then that's awesome!