Thank you Chicken and Sparky for taking the time to help.
Still having a bit of trouble getting anything to show up.
Here's what I did referring to both of your instructions.
-Created new.php, pasted the code into it, and made sure file was in whmcs root directory, which is actually "whmcs" for this test.
-Changed this line: $breadcrumbnav = '<a href="index.php">'.$_LANG['globalsystemname'].'</a> > <a href="mypage.php">My Page</a>';
require("init.php");
To this: $breadcrumbnav = '<a href="index.php">'.$_LANG['globalsystemname'].'</a> > <a href="new.php">New Page</a>';
require("init.php");
Then changed this line:
$templatefile = "homepage";
To this:
$templatefile = "new";
I saved the file, then copied the code and pasted it into a new file called new.tpl, saved it, and then uploaded it to whmcs/templates/portal, then browswed to mydomain.com/whmcs/new.php
Still no luck getting a blank shell to show up. Do you see anything I've done wrong, or perhaps I missed something simple? I'm obviously not a programmer, but I hope I can crawl my way through this with your guidance.
Thanks again to both of you for helping.
Selym