I need to set up a root basic template file for my website. All my pages are based off the SAME design, just different text.

I want to (and I know its possible) have lets say the index.html as the root template. So if I change a link in the navbar on index.html, it changes the link automatically for EVERY single other page on my site. So I dont have to go through EACH page and change the one link in the navbar.

You want to use includes.
You just need to break your page apart into sections.
Common content across all pages can be included, reducing creating the same code for multiple pages.

Also perfect for your menu, when you want to change content, you just change one file and everywhere it's included it will be the same.

I did a quick Google, and these look pretty good for the concept.
http://www.apaddedcell.com/how-autom...ter-every-page

http://www.isitebuild.com/php-include.html