Just be yourself, take the courses offered and move forward. They love it when you show interest in your work with them and that you are willing to do whatever it takes to advance in your job.
Don't attend it, save your energy, you don't need a meaningless job, if you have another interview, ace that one instead.
They always have applicants that don't show up for their interview cause they made the right decision - attend another job interview
Dont do it go flip burgers or something else its not worth being in debt for a job your just starting.
Be honest, show ambition