Well in this case it seems that you have not installed the script at all. You have to run the installer script, its not installed for you just because you upload it through ftp. Before installing the script, you need to create mysql databases and users first. You can do this in PhpMyAdmin.

Which is weird, because I did make a database and user. Can I just PM you my ehost login info, so you can sort this out?

Well in that case you need to add the user to database, give the user full permission to access the database. If you use CPanel, it should be easy and straightforward.

Did that through the wizard, full permissions. But when I go to (mysite).com)/install/ and type in all the info, it gives me the "something was left blank" error. I'm confused.

Well did you leave some fields blank? Post a screenshot of the installation page prior to where you got the error message(with password censored of course), I will take a look.

http://imgur.com/a/ukeDt

Here you go.

Well I don't see anything that is left empty, but your script path is incorrect, it should be the part after public_html. So remove this and leave the value empty, and try again. Then lemme know what happens?

The problem was solved! Apparently, I played around with code where I shouldn't have, and a fresh upload fixed it.

I see, glad it was fixed for you. I hope my advice helped, you aint supposed to write 'public_html' in your script path really.