Did God walk on earth

A:

If we accept The Bible as a reliable record of events, yes - God did walk on earth, and was seen in human form.

One example, from the anonymous source now known as the Yahwist, is in Genesis 3:8: "And they heard the voice of the LORD God walking in the garden in the cool of the day: and Adam and his wife hid themselves from the presence of the LORD God amongst the trees of the garden." The Yahwist represented early traditions from the kingdom of Judah, and presented God as anthropomorphic, or human-like.