This tutorial is for installing WordPress to power your entire website. You should modify the instructions accordingly if you wish to install WordPress in a subdirectory (in particular, don't remove your existing web directory and extract WordPress to web/wordpress or some other directory).
Before you install WordPress, you will need a MySQL database. If you requested one when your account was created, you can find its password in an email that was sent to your group account's inbox. If you do not have an account, please request one by emailing help@hcs.