Drupal exposed view

is there a way to not display any results initially until the form has been submitted?

Also, I cant see where I can override the exposed form

As @googletorp mentioned, you can override the expose form using hook_form_alter(): check out a couple examples in other questions to get an idea of how it works:

• remove a logic operator(unlocked) of a exposed filter
• Supplying a predefined list of options for an exposed item in a view in Drupal?

To display a blank form unless the user fills out the exposed form, you can use hook_views_query_alter() in a custom module:

function test_views_query_alter(&$view, &$query) {
  $filter_set = FALSE;

  foreach ($view->filter as $filter) {
    // Check if we've found a filter identifier that is set
    if ($filter->options['exposed'] && array_key_exists($filter->options['expose']['identifier'], $_GET)) {
      $filter_set = TRUE;
      break;
    }
  }

  // If the filter isn't set, add a WHERE clause to the query that
  // cannot be TRUE. This ensures the view returns no results.
  if (!$filter_set) {
    $query->add_where(0, 'FALSE');
  }
}