tabernacle
Moses was given instructions as to how to build the tabernacle.This is recorded in the Book of Exodus.
Moses
The tabernacle was built according to the instructions given by God to Moses, with the help of skilled craftsmen and workers chosen by Moses. It was constructed by the Israelites during their time in the wilderness as a place of worship and to house the Ark of the Covenant.
Moses was given instructions by God for the Tabernacle, the mobile shrine by which he would travel with Israel to the Promised Land.
The book of Exodus ends with the completion of the Tabernacle and the glory of the Lord filling it. Moses then enters the Tabernacle to speak with the Lord, symbolizing the presence of God among the people of Israel.
Answer from Scripture:Exodus 33:9-11a - And it came to pass, when Moses entered the tabernacle, that the pillar of clouddescended and stood at the door of the tabernacle, and the Lord talked with Moses. All the people saw the pillar of cloud standing at the tabernacle door, and all the people rose and worshiped, each man in his tent door. So the Lord spoke to Moses face to face, as a man speaks to his friend. [NKJV]
If you mean the Moses of the Old Testament in the Bible, "churches" as buildings did not exist in his time. Jews of his time went to the tabernacle (a large tent used for worshiping God), so that is where Moses would have gone.
After Moses assembled the Tabernacle, God's presence manifested itself in a Cloud of Glory (Exodus ch.40). Shortly after, when the first offerings were made by Aaron, God caused them to be consumed by a miraculous fire (Leviticus ch.9).
tabernacle
In the bible it is said Moses saw Gods back only.
In speaking of the Tabernacle that God instructed Moses to build with specific details. It is to help all people of every nation understand His redemption for the sinner and show the pathway to His Holy throne where after being purified you may enter boldly.