How to dislodge drupal from Apache and remove drupal
Yes, deleting the files and dropping the database should be enough.

If you made any changes to Apache (eg. creating a virtual host) and/or the operating system (eg. a line in the /etc/hosts file) you may want to revert that as well.

Don't worry about messing it up the first time, that's actually a great way to learn and get comfortable with any CMS (not just Drupal).