You did a pretty darn good job for your first attempt.
I just brightened the image, added a little contrast, adjusted the color temperature, and there you have it. The fine details of your figure were in your original image, they just needed brought out a bit.
The most important piece of information is what kind of lamp bulbs to use. "Soft white" bulbs (I believe you used these) make your image very "warm" or yellow. "Day time" bulbs make your image "cool" or blue. If possible, try to invest in 3 lamps.
For backgrounds, use one large piece of posterboard and curve it. This creates a seamless background and can be switched out for different colors.
Don't get discouraged if your lightbox photos don't look as good as others. A lot has to do with manipulating your camera settings and doing some editing.
If you have any questions, I'll gladly answer them