How to get a term_id on single envent page

Please see if I can help it, because I have already a couple of days trying without success. Needed to get the term_id of an event (Single page event). I copied the methodology used in the plugin, declare the instance and then try to bring the value, but does not leave me. And also I declare global variables . Excuse because not much of php.

global $wpdb, $blog_id, $wp_query, $booking, $post, $current_user;
$event = new Eab_EventModel($post);
echo $event->term_id;

Tambien probe con....
$event = $event instanceof Eab_EventModel ? $event : new Eab_EventModel($event);
//$event = ($post instanceof Eab_EventModel) ? $post : new Eab_EventModel($post);

Thanks in advance