Server Error message whenever I choose a template to start to use Website builder

I am trying to use the new Website Builder for a brand new domain name purchased yesterday.  The first step is choosing a template, so I choose a template and it takes me to an error page every single time, not matter what template I choose.  The error message is:

 "Sorry, you have experienced an unexpected server error.

You have experienced an unexpected server error. We are working to resolve this problem as quickly as possible. Please try again later."

I cannot get past this error message to build my site.  I need to get a site up and running this week.  Can someone tell me if this new Website builder is ready for use?  If so, what needs to be done to get that error message to stop so I can continue with my build.  I don't look forward to learning a whole new method of building my site, but am willing.  It just needs to work.

Thank you