Simple Animation Problem

I'm a Newbie with CC, so I'm stumbling around. I'm trying to set up an anim with, at the moment, three files. In the Window I have time line checked, but the time line is not activated. In other words I can't do a thing; can't figure out what I've done wrong. The only thing I've been able to select is the button in the center of the time line, and it is set for "Create Frame Animation." Any thoughts greatly appreciated. Thanks.