If you want to let users manage the Events, they need to have the right access in WordPress role. MEC follows the WordPress role and capability. If you need to use another one of the WordPress or use a custom role, you need to use an extra plugin and this table.
Important knowledge: If you want to change the date format on a single event page (frontend of the single event) you need to go to WordPress Dashboard > Settings > General > Date Format (and also time).
https://webnus.net/dox/modern-events-calendar/frontend-event-submission/
