Im a brand new user (today, Sept 30) and have plenty of questions.
first is phone support available?
and what do we do until the material library is available for us Mac users?
Hey @drawskip
Welcome to the Enscape Forum! There is no phone support available, but you can send in a support ticket directly through the software - use the “Feedback” button - if you run into any issues.
For first steps however, why don’t you check out my tutorial on Enscape for SketchUp on Mac:
I explain in some detail how you can create your own high detail materials, so that’s the best thing to do to make up for the missing material library 
Thanks Kaj!