The navigation bar is in the header.php and not in the different page files.
As you are saying that you want to hide the menu for a single template rather than a specific page, another way would be to move the navigation bar code into a template part, and add this in each page file.
So you would remove the 'access' block of code from the header.php, paste this in a new file called navigation-1.php, then in the different page files, like index.php, archive.php, single.php, page.php, search.php, add a call to the menu.
in the different page files after the get_header()
<?php /* Get our navigation bar */ ?>
<?php get_template_part( 'navigation', 1 ); ?>
This tutorial on adding a second menu may help!
If you are not using a child theme then you may want to look at the other tutorials and posts.