I didn't think so, but just to make sure, I deleted everything and reuploaded and installed it, but I still get that. :(

In most cases this is because you've specified incorrect domain and/or script path in your config file. You need to check the values in inc/config.php, the scriptpath may not exist. Also keep in mind that it is case-sensitive.

I checked and anything other than gardencreaturesnet.ipagemysql.com makes it so that I can't even view the page; it gives me a MySQL error saying that it can't connect to the database

umm wait a minute, are you running a site with subdomain in this format?
If so, yes you get a problem. The fix is pretty simple though, go to class_page.php and class_pagination.php and search for 'www', remove them all and you will be fine.