You will see duplicated line close to your original line. Now you have internal and external wall of your vase. The space between them define the thickness of vase. Move your mouse until you get the desired thickness.
Now you have finished shape of half section of the vase. Let's pottery!
Click on Line in
Modifier List to unselect
Spline editing mode and open the
Modifier List listing. Click on
Lathe. You will something like screen below. Don't scare, now we set this and it will be ok.