Do you get an extra turn when you promote your pawn? If you promote a pawn do you get a second move to move it out of danger? Or do you still only get the promotion as your move and it becomes the opponents move?
Once you have promoted your pawn do you get a second move to move it out
  of danger?


No.


  Or do you still only get the promotion as your move and it becomes
  the opponents move?


Yes.

From the FIDE Laws of Chess:


  3.7.e When a player, having the move, plays a pawn to the rank furthest from
  its starting position, he must exchange that pawn as part of the same
  move for a new queen, rook, bishop or knight of the same colour on the
  intended square of arrival.


There is no discussion of extra turns.