Scheduling Center config question

Summary

I am configuring the Scheduling Center and am having some trouble with the required Internal and External messages on the setup

Content

I was wondering if anyone could provide me some advice/pointers on an issue I am having.  I am configuring the Scheduling Center and can see the emails that are delivered in the Scheduling Center.  But then it also asks me to create an internal and external message to be used in the configuration pages. When I went into Recruiting to create the message templates, I can't find any variables to put into the message to ask them to register for an interview.  And I can't figure out how to get the emails in the Scheduling Center to actually trigger.  Am