Using 'more' tag not working

I’m trying to insert a ‘more’ tag into a static page and it’s not working. I’ve been told I need to insert the following code into the ‘loop’:

<?php
global $more;
$more = 0;
?>
//The code must be inserted ahead of the call the_content, but AFTER the_post()

<?php the_content('Continue Reading'); ?>

But there’s no loop.php in my theme (child theme of Superhero). Will the loop be in index.php? I’ve looked and I can’t decipher where exactly to inser the code.

Any help will be appreciated.