This module is an assignment.

It has two separate blocks:
  1) show visitors counter, which is stored in a file (CountVisitorsInFileBlock.php);
  2) show visitors counter, which is stored in a DB table (CountVisitorsInDBBlock.php).

To install package run "$ composer require lorik/fortune_number" in your console.
Then go to http://assignment.test/web/admin/modules and install module via name 'Fortune Number Module'.
After that go to http://assignment.test/web/admin/structure/block/list/olivero and enable blocks 'Count Visitors in DB Block' or 'Count Visitors in a File Block' to your page path or '/indexAction/page' (path for this module controller).