Well, I am quite certain I have thoroughly figured out how to not
properly use the twig templates - maybe someone can help point me in the right direction:
I created a new page (checkout.php) and uploaded it to the server. The page contained the header, footer and an open container for the body.
Where I would normally insert the ^^cart^^ placeholder, I inserted the cart.inc.twig code
downloaded from the https://wiki.foxycart.com/v/1.1/templates
After uploading the file to the server, I went back to the Foxycart Admin and navigated to the Cart section, entered the URL to my checkout.php page and cached it.
The result was anytime I called the cart via my links/forms, a blank colorbox loaded.
Thanks in advanced