Hi Tonia,
Thanks for taking the time to reach out, and I’m so sorry for the trouble here! This issue can occur when you have a number of plugins enabled that add their own columns to your post (and/or custom post type) listings, such as SEO plugins. When viewing your event listing as seen in this screencap, simply scroll to the top of the page, click the Screen Options tab that’s displayed there, and uncheck the boxes for any columns that you don’t need. Save your changes, and once the page refreshes, you’ll see the remaining columns expanding to fill the available space.
I hope that helps! Thanks again, and if you should have any other questions, please don’t hesitate to pay us a visit over on our WordPress.org support forum! 🙂