Hi Kiki.
Take a look through this file: /wp-content/plugins/the-events-calendar-community-events/src/views/community/edit-event.php
In that file, search for ‘do_action’ to see all the places you could insert custom content.
For example, you could do this by adding the following code to your child theme’s functions.php file:
by adding this code in your child theme’s functions.php file: https://gist.github.com/cliffordp/6ed4de93895fe2acd959
Again, you could use ANY of the action hooks in that file to put your “Notice” text somewhere else (e.g. at the bottom of the form).
Let me know how it goes for you.