Howdy Dorothy,
I would love to help you with this.
It sounds like you might be interested in this tutorial: New User Primer: Event Tickets & Event Tickets Plus
One of the most important steps is step 4) of that tutorial, where you install and configure an ecommerce store. Once one of those is active you will have a new option on the tickets screen to add a purchasable ticket, just like you’re looking for.
The most popular ecommerce store by far is WooCommerce, and they have a pretty solid guide for installation. Once it’s installed it’s pretty userfriendly, and makes it about as easy as possible to get setup so that you can actually accept credit cards and such.
Does that all make sense and answer your question? Please let me know.
Cheers!
– Brook