Hi Brad!
Thanks for reaching out to us! 🙂
If you want to sell tickets you might want to check Event Tickets Plus which will allow you to create tickets for your events and sell them through a third-party ecommerce plugin like WooCommerce.
If you just want to show a text to all the events that says “Click Here to Purchase Tickets”, then you can do a template override and add that text. There’s a great article where you can find a Themer’s Guide here > https://theeventscalendar.com/knowledgebase/themers-guide/
I hope that helps and let me know if you have other questions.
Best!
Victor