Is there a shortcode or other way i can make it so that once an event has occurred it is removed from the calendar?

Hello Becky!

Thank you for posting your inquiry!

Unfortunately Spider Calendar does not have the mentioned functionality. However, you can unpublish the past events from back-end of your website, and they will no longer appear on calendar page.

Hope this workaround is a suitable solution for you.
Thanks! Have a wonderful day!