I solved this problem and should have posted my solution earlier.
It turns out that because of the default permission settings (which couldn’t be changed) assigned by my web hosting service to the files and folder I uploaded via FTP, my plugins were not functioning properly.
My solution was to switch web hosts. With my new host, and the correct permissions being assigned, I’m getting full functionality not just from WordPress SEO by Yoast but from the other plugins I am using.
Now that I can actually use it, I highly recommend WordPress SEO. It’s really working great for me and my first website.