Hi there, Erin! Thanks for getting in touch and welcome to the forums. 🙂
Great question. Unfortunately, grouping tickets by category isn’t currently a feature that is supported right out of the box. We’ve had a similar request for such a feature on our UserVoice page. I’d encourage you to add your vote if you’d like to see it in a future release, or submit a request of your own so others can vote on it as well.
That said, you may be able to accomplish this with some custom development. I do want to note first of all, though, that we are fairly limited in terms of helping out with custom development questions. We’d love to point you in the right direction if we can.
One idea is to override the ticket form that displays on the single events page. Check out our Themer’s Guide for more information on how to override calendar plugin templates in your theme. In this case, the temple you want to override is located in /wootickets/views/wootickets/ticket.php. Once that is in your theme files, it can be modified to fit your needs.
From there, you might be able to customize the code to display tickets by looping through product categories. Product categories are handled by WooCommerce, so you will want to refer to their documentation for more information.
Sorry I don’t have a more concrete answer, but I hope this helps point you in the right direction. 🙂
Cheers!
Geoff