Hi Ayan!
Thanks for reaching out to us! 🙂
If you want to customize the template files that show the submission form, there is a great article that explains how to do that here > https://theeventscalendar.com/knowledgebase/themers-guide/
You might want to start by overriding the template in your own theme by creating a file at your-theme/tribe-events/community/edit-event.php. Then you should copy the contents of the template file edit-event.php located at wp-content/plugins/the-events-calendar-community-events/src/views/ and paste it in file you created.
I hope that helps and let me know if you have other questions.
Best!
Victor