Hi, fravaro. Thanks for getting in touch about your customization.
For information on how to override the default templates for WooCommerce Tickets and The Events Calendar, your best bet is the Themer’s Guide, linked in the right sidebar. The files relating to sending tickets are tickets.php and email.php.
For complete documentation on the plugins themselves, please check out our Technical Documentation, linked at right.
Please also remember that WooCommerce Tickets is basically an add-on that provides integration between TEC and WooCommerce. If you need things on the WooCommerce side customized, your best resource would be the WooCommerce Ninjas.