What should I do when I return to the starting point and the end point?

How old are you? I still can't feel it for 20 days. In fact, it is very simple to judge whether the car body is right or not. You sit in the driver's seat, twist your head to see if the yellow line on the left is parallel to the car body, then look at the position of the front of the car, look farther to find a reference, and then practice repeatedly to find out the feeling of the car body.