First attempt incorporating backbone.js in my code
Alternative Approach:

In your case, I believe that the use of a model is not really necessary for this task.  I would construct this using a master view with child views for each step:

A TourView that contains a variable tracking which step is currently active and listenting for an event from it's child views for navigation.

A TourStep1View .. TourStepNView for each step of the tutorial whose render function contains corresponding show and close function contains the hide.

Launch the TourView and have it render a child view for the first step.  The child view should throw an event to signal the parent view to swap it out for the next child view.