What shape of the orbit does the Earth have?

Earth’s orbit is not a perfect circle. It is elliptical, or slightly oval-shaped. This means there is one point in the orbit where Earth is closest to the Sun, and another where Earth is farthest from the Sun. 

To know about the types of orbits, visit the linked page.

Further readings- 

1. Earth – Origin And Evolution
2. Motions of the Earth