I also prewind a few bobbins because it is more convenient to prewind a few bobbins before starting. If you are using your machine to do machine quilting, the thread will show on the back of the quilt and would be prone to thread breaking from use. So, you might want to change the the thread in the bobbin to match the color of the backing of your quilt. Since this is a new machine for you, I'd practice quilting/embroidering on some test fabric for the project you are stitching, or on a practice quilt sandwitch. If the shop you bought it from has classes, it'd be a good idea to sign up for one.