So, without any in-depth knowledge of .php, how in the world do I even begin to think about editing the left-hand nav bar so that my forum begins to match my website?
You would want to modify the panel.php file found in the themes folder. First, you want to create a new folder in the themes folder called myvanilla or something of your choice. Then you would copy the panel.php file and put it in the my vanilla folder. Then modify that version. You'll also need to copy the appropriate styles folder and it's sub-folders, too.
The generic panel.php file has nothing in it. I would suggest downloading the Blogger theme and see how that author has modified the panel.php as an example.