First, just draw a regular star. But make sure it is big and neat that everyone can see clearly.
Now just erase all the lines you have made in the star.
Now draw lines from the points of the star to the points that are jutting in like you see here. Curve in the lines just a little bit that you can hardly tell. As you can see, you can hardly see the curves. So do it like that to make it look 3D.
This last step is really easy. Just color in the right side of every triangle like shape. You have now finished your 3D star!!!!!