Motion Path Loop

In general:

      Move object 1 on motion path X when you want the first path to begin

      Move object 2 on motion path y when motion path x ends

     Move object 3 on motion path z when motion path y ends

     Start fire Flickering when motion path z ends

In your case, (assuming you want to allow initiating the motion paths in random order), You need this trigger for each of the 3 groups:

Then you need another trigger like this  for each group;'

Be sure each group has a trigger to set its variable true and that the variable is set to true when the learner clicks, not when the motion path ends.