“The glory of Yahweh stood there.” In this case, what Ezekiel saw was the brilliant cloud that surrounds Yahweh, with Yahweh in the middle of the cloud, just like Ezekiel had seen in Ezekiel 1:27-28. The text could have just said “Yahweh” because Yahweh was personally present in the cloud of glory, but it says “the glory of Yahweh” because that is what Ezekiel saw.
The Tanakh version by the Jewish Publication Society clearly understands that the “glory of Yahweh” surrounds Yahweh and thus indicates His presence, because they translate Ezekiel 3:23 as: “I arose and went out to the valley, and there stood the Presence of the LORD, like the Presence that I had seen at the Chebar Canal….” [For more on the glory of God, see commentary on Ezekiel 1:28].
“and I fell on my face.” This is a very appropriate response to being in the presence of Yahweh.