happy to hear you have a child theme set up.
i don’t have access to your theme files since it does not seem like the theme is from www.remarpro.com
i could show you generally how i would do it for themes i use but you would need to adjust for your header.php file
conditional statements/tags sometimes takes a few tries to get it right. but the format you want is something like
the general idea is….modifying the header.php file of child theme…..
create a control like this: if the current page is not pricing page then show menu
conditional statement/tag might look something like this….
<?php
if ( ! is_page( in this space put the page id of your pricing page) )
{?>
in this space put the information related to the nav menu code used in the header file
<?php } ?>
note: !=NOT