how do i create hidden pages with this theme

1. It’s the best to ask the author(s) for a readme, instructions etc.
2. Normally there should be in one of the template files (presumably in header.php) a line like this:
<?php wp_list_pages('title_li='); ?>

just add an exclude parameter as described here:
https://codex.www.ads-software.com/Template_Tags/wp_list_pages#Exclude_Pages_from_List

e.g. <?php wp_list_pages('exclude=XX,YY&title_li='); ?>
where XX and YY are the page_id #s of the Pages to be excluded.

Moshu,
I found it and it looks like this;

<?php wp_list_pages(‘sort_column=menu_order&depth=1&title_li=’); ?>

should I be inserting the code b/w the “1” and “&title” or do I stick it at the beginning of the parentheses– before “‘sort_column…”

Make it
<?php wp_list_pages('exclude=xx,yy,zz&sort_column=menu_order&depth=1&title_li='); ?>

Notice the comma between the numbers and the ampersand between the last number and sort_column.

Conversely, couldn’t we just delete that php code that you listed above and just create a new <div> called “navtab” within the header.php and manually list the pages that we want as navigational tabs?

At the same time, we achieve the effect of not having to manually insert the pages that we want excluded by using the exclude tag?

Basically – yes.
I am not familiar with that theme at all, so don’t blame me if anything goes wrong ??
Probably you don’t have to create a new div, just put the pages in <li>..</li> tags = the template tag above generates a list, that’s why you should put every Page included in its own li.
Back up every file you are going to change.