Hi,
Thanks for using our plugins. I can help out here.
Tickets can be bought from the shop page, but the Category Viability has to be set to show there.
You can find that setting in the Publish Box for each ticket product, that is in the Product section and not in the event itself.
If you always want them visible as by default they are hidden you can use this snippet to do that for all new tickets:
https://gist.github.com/jesseeproductions/5768685acc4cd48cdd81
Add that snippet to your theme’s functions.php to change it.
Let me know if you have any follow up questions.
Thanks