Blog posts are being listed under content I know nothing about Drupal, trying to help a friend out. 

Right now blog posts are being listed under /content [site.com/content/blog-post-title] instead of /blog. 

I'm trying to figure out where to look to figure out why.
The fact that blog-post-title appears suggests that the module PathAuto is somehow involved.  Try to disable that module (If you're on Drupal 7, navigate to Home » Administration » Modules, locate PathAuto and remove its tickmark, then press "Save configuration" and clear all caches.)

If the blog posts now appear under /blog, you know why.

After you've etablished that PathAuto is indeed resposible, you can re-enable the module (all its settings will be left intact), and you can then proceed to change its settings to put blog posts in the place you want them.