1. In that same file, study the way Zen Cart links are used. You should be able to figure it out. Zen Cart uses it's own functions to create the links dynamically. The structure of the links is HTML with PHP scripts inside. If you are familiar with basic HTML, you should be able to see how the links are being created. Tinker a bit - best way to get comfortable with the structure. SSL, NONSSL tells the ZC function to create the link with http (NONSSL) or https (SSL). Most of the time NONSSL is sufficient. Any links that require secure session you would define with SSL (ex. Login, Account Creation, Checkout). Zen Cart session id's will create automatically.
2. Admin>Layout Settings>Categories-Tabs Menu ON/OFF - Turn OFF
3. change
Code:
<?php echo HEADER_TITLE_CHECKOUT; ?>»</a>
to
Code:
<?php echo HEADER_TITLE_CHECKOUT; ?></a>
(removing the »)