Well first off, congrats on getting your tablet. The more you practice with it, the better you will get. It won't take long. As for the anatomy, her breasts are too high up. Luckypan and Lintu both have good tuts on how to draw the female chest c: [link] and [link]
There are many other tuts out there on female anatomy c: You can also look at stock photos for references.
As for the lines, those are really good for your first time using a tablet! To give your picture more depth, try using different sized lines for the picture. Like, the lines for the hair could be thicker than the ones used for her main body. Now that you have a tablet, don't be afraid to experiment with your style.