How to create an independent page?

Question

Drupal

I have been trying with Drupal for a couple of days. I use the seventh version (7.67). There are standard theme pages.
page.tpl.php , nodes.tpl.php . How to make an independent page, for example, custom.tpl.php, without the possibility of customization, which opens at site/custom ? . Like view/controller in framework.
I will display content on this page not even from the database, but from other sites

Answer 1

function mymodule_menu() {
  $items['custom'] = array(
    'page callback' => 'mymodule_custom',
  );
  return $items;
}

function mymodule_custom() {
  echo 'custom';
}

https://api.drupal.org/api/drupal/modules%21system...