I created a moving platform (animation) and attached a box collider to it, but when my character is standing on it he doesn’t move with it, he stays in the same place as the platform slides out from underneath him (if you get my drift). Anyone have any advice? 
Try making the player a child of the platform while he is in contact with it
A bit late maybe, but here is a guide we wrote just in case:
http://spacelizardstudio.com/devblog/index.php/2016/03/02/unity-a-guide-to-moving-platforms/