CiviCRM Event - Event Confirmation EMail
Welcome to Stack Exchange! 

You can edit any emails that are automatically sent from the System Workflow tab on this page - /wp-admin/admin.php?page=CiviCRM&amp;q=civicrm%2Fadmin%2FmessageTemplates&amp;reset=1

You're able to edit any email templates that are generated from the system such as event emails, membership emails and contribution emails.

Hope this helps!