When I first created my website I overwrote the wordpress php and essentially made the website static. Now I want to make one specific page wordpress compatable (e.g. when i make posts from the dashboard they'll appear on the page), and it is not the index. Which files will I have to redownload and what do I have to do to achieve this?
Download and install a full copy of Wordpress to a sub-directory on your site. Having it in a sub-directory won't interfere with any of your static pages in the root directory, or elsewhere on the site. The sub-directory for Wordpress can be named whatever you like; you don't have to name it /blog.