I've been doing this site for several years and several versions of Drupal.
It has a CLE Registration System, Room Bookings, Memberships, etc.
The client does all the events, bookings, memberships and most of the content.
We admin the mail, web, ecommerce and dns.
This a bootstrap theme, optimized for mobile.
Ecommerce is Drupal Commerce with a Stripe gateway.
Due for a redo after PHP 8 is a little more readily available.