Drupal\\node\\Entity\\Node Object ( [in_preview] => [values:protected] => Array ( [vid] => Array ( [x-default] =
To build on VJamie's answer.
You will need to either set a use statement at the top of your script;
use Drupal\taxonomy\Entity\Term;
Or, prefix the class instance with the namespace;
$term = \Drupal\taxonomy\Entity\Term::load($node->get('field_destination')->target_id);
That will get rid of the fatals.