Drupal 8 can handle simple sites such as this one, of simple pages.  For the sidebar Calendar, I added the Calendar (includes Calendar Datetime) and Views Templates modules.  There was not a Views Template for a simple Calendar, so I used the template to 'Content Authored On' and edited the view to filter for CT 'Article' only.  I do not create Articles.  So far only Basic Pages and Blog Posts in this site.