Chickenbone John “The Godfather of the cigar box guitar”
https://www.youtube.com/user/ChickenboneJohn/videos
Many videos on playing and building
Justin Johnson
https://www.justinjohnsonlive.com/
Many videos on playing and also paid courses
He has a good video on intonation https://www.youtube.com/watch?v=IPTQmyNbwpY
LearnCigarboxGuitar.com
https://learncigarboxguitar.com
Check under “free stuff” in menu, he has several pretty good instruction videos and a knowledge base. I have not looked closely at his paid courses yet.
Del Puckett
https://www.youtube.com/c/PuckettCigarBoxGuitar/videos
He has many videos about building and playing CBGs.
Mike Snowden
He has videos on playing
He also has a video on setting intonation
Shane Speal “The King of the Cigar Box Guitar”
He has many videos on playing
Shane’s videos
https://www.youtube.com/playlist?list=PLpET_ZZI7rmROAInFkbD9szyuIXn2zM-T