Teams issue with files and Sharepoint backend

Greetings!  I am an experienced Teams admin and work with multiple clients.  I'm now working with a non-profit organization with Microsoft Office 365 Basic licenses.  I set up a Team in the usual way.

The backend SharePoint site gets created.  But for some reason, users can't get the file store.  I've included screenshots below.  Would appreciate any suggestions!  I've included screenshots below