An oval looks like a stretched circle.
The orbit with which our earth orbits the sun is also a slightly stretched circle.
Exercise 1: Draw a sun. Make continuous oval orbits around the sun as if you were a planet repeating the same orbit again and again (image).
Exercise 2: The shape of a circle, small or large, always remains the same. Ovals can do much more: they can be rounder or flatter and point in all directions. Draw different kinds of ovals: flatter and rounder and in different directions.