Hi there, Louise! Welcome back to the forums–nice to see you again. 🙂
Adding custom fields to the Community form is a lot easier if you have The Events Calendar PRO. The PRO plugin includes the ability to include additional fields for events that will automatically display on the Community Events form (screenshot #1, screenshot #2).
Getting additional fields in the form manually will take some custom development. I do want to note that we are fairly limited in terms of helping out with custom development questions like this, but I’d be happy to point you in the right direction, if I can.
If you were able to create the additional field in the WordPress admin view, then your next step is to create a method for calling it. Once you have that, you can customize the edit-event.php template to include it where you would like it to display.
Check out our Themer’s Guide for detailed steps on how to override calendar templates without touching core files. This will walk you through the process step-by-step.
Does this help answer your question? Please let me know. 🙂
Cheers!
Geoff