Basic 101 Please answer Black Players

I wonder why / how anyone ends up playing Black?

Isn't Black decisively disadvantages against White's opening?

Please point me to videos or training that helps me as a voluntary Black opponent?

Thank you! 

In other words, why doesn't white always play the Andersson Opening if Black ever has an advantage?

This is an odd question given your example of the Andersson opening which immediately gives black an advantage. White gives up the initiative in the middle of the board, and black tends to do very well against this opening.

As for why anyone would want to play black. In general black gets to dictate what type of game is played. The majority of openings are defined by black's first or second moves. Yes white tends to have a slight advantage with most openings, but it is really negligible up to very high levels of play.

Advantage and decisive-disadvantage are not the only two possibilities. The truth is somewhere in between.

I've been playing off and on for six months and I have to say I enjoy playing as black.