Thank you for your patience...I am using CP9.
I found the Variables, under Projects, and I think I have set it up (though if you included a sample of what it might look like I could replicate it). I don't know what to do next. I don't know what the Advanced Action should look like. Nothing I set says "Execute Action."
BIt more complicated than in CP2017 (have a full descriptive blog psot about the Advanced Actions dialog box for CCP2017).
Variable:ue (that is gone in CP2017):

Advanced Action, first decision TrackVar needs a conditio that is always true:

Second Decision CheckVisit, THEN part:

ELSE part:

When this is created, choose the action 'Execute Advanced Actions' for the On Enter event of the slide, and choose the action you just created.