No, You Can't See the Great Wall from Space

Not with the naked eye, anyway. NASA:

It has become a space-based myth. The Great Wall of China, frequently billed as the only man-made object visible from space, generally isn't, at least to the unaided eye in low Earth orbit. It certainly isn't visible from the Moon.

With the zoom lens on an ordinary digital camera you can see parts of the wall, but also lots of other human-built things, like airports, dams, and the like.