how to load wordpress code into subdirectories

Hi!

so mysite.com is up and running with a custom front end and a wordpress backend (to allow my friend to update via her wp dashboard wherever i’ve inserted a wp loop). do i have to reinstall wordpress entirely in mysite.com/resume ? i tried just inserting index.php in the resume subdirecotry but it doesnt work. I dont want to use a page template because mysite.com/resume needs a completely different design from mysite.com/production, etc…

for each link on the navbar id like to design the page for that link from scratch.

help please!