The Lord is one

Can plurality exist in 'echad'? What does it mean when Jesus said the Lord or God is one?
Heard the good news?
https://rumble.com/vm9asu-the-gospel.html

Scriptures addressed in this video:
Genesis 2:24
Exodus 36:13
Deuteronomy 6:4
2 Samuel 2:25
Mark 12:28
Mark 12:29
Mark 12:30
Mark 12:31
Mark 12:32
Mark 12:33
Mark 12:34