Addon Domain Installation Headache

Hi everyone,

I’m not too sure if this question would fit here, but I don’t know where else to ask this.

I am trying to park my new domain on a paid webhost, which already has a primary domain on it, that being one of my dad’s sites:
https://pmrenglish.com/

I went through pretty much the same steps on this online guide.
In regards to the Name Server, I used the same ones provided for the primary domain (pmrenglish.com) above.

After that, I used Fantastico De Luxe to install WordPress 2.8.4.

Here’s where the trouble starts.
-When I try to go to my addon domain, aprilius20.com, Google Chrome tells me “Oops! This link appears to be broken!”

-When I created the addon domain through cpanel, a subdomain was somehow created. I tried to get rid of it but was told that I’d have to delete the addon domain to do that.

-The only link I can go to is this one, which gives me a plain text version of the wordpress blog’s main page- “Hello World!” and all that.

-On that page, I tried clicking on the “Log In” link, which does redirect me to what seems to be the correct address:
https://aprilius20.com/apripii/wp-login.php
…but then gives me the ‘link broken’ error again.

-How do I get to aprilius20.com? Or aprilius20.com/apripii without getting screwed up?

I apologize if this isn’t the right place to ask this, and if I haven’t provided enough information.

Thanks for any help,
Aprilius20