If we were standing on mars which direction would the earth be moving at the begining of the retro grade motio

If you were standing anywhere on the northern hemisphere of Mars, facing the Sun (and assuming that you could see Earth, despite the glare from the Sun),
AND if you ignore the daily motion (which causes everything to rise in the Earth and set in the West every day), then you would see Earth move from the left of the Sun (as seen by you, on Mars) to the right of the Sun, passing (almost) between Mars and the Sun.

That is the time period during which the rest of us, still on Earth, would see Mars appear to be in retrograde motion relative to the fixed stars.

The Earth would move westward toward the Sun from its greatest eastern elongation this is when Earth is farthest east of the Sun in Mar's evening sky. At this time Earth would be an evening "star" in Mar's sky. Very similar to what we see when Venus is the evening "star". Earth would continue its retrograde motion until it reaches its greatest western elongation as Mar's morning "star"

Westward.