I've been looking at YouTube for BCM BCG cleaning videos and can't seem to find anything great. I'm not sure if every BCG is essentially the same and broken down the same or not. I'm going to get my first AR in a few months so I'd like to research this first. Are there any good videos that I can look at?

I would suggest starting with looking at the front page of the maintenance & cleaning forums and look at the lubrication points thread because it covers the BCG components and oiling points.  Being former military I tend to go with what I learned and continue to learn for PMCS however, if you are getting your first AR I would strongly suggest searching through arfcom's archives and reading as much as you can about the platform starting with safety.  

BCG maintenance has also been covered here on arfcom if I am not mistaken.  To answer your question yes every BCG be it semi or auto that I have broken down is essentially the same.  I hope this helps, welcome aboard, good luck and safe shooting !  ETA content.

If you've narrowed down the manufacturer of the AR you would like to purchase, I would suggest looking on their website for a resource page. Download any tech/owners manuals they have. Study those.