Kindly remove the index.html file from your home directory(if any).
There is only index.php do I need to remove this?
Your domain, although pointing to Hostgator, isn’t configured properly at Hostgator to point to your WordPress installation. Check the settings for the domain in your hosting panel.
Check the domain settings in Hostgator or in Godaddy?
Im sorry that it might be stupid question but I am very new to this and don’t know much about hosting or website
If you don’t mind, can you please tell me what I need to do in more detail?
Your domain is happily arriving at Hostgator, and the Hostgator servers are happy to receive it but you didn’t tell them what to do with it. So, in your Hostgator hosting acount, there will be a place where you can set up domains. I don’t use Hostgator but it’s probably something like cPanel.
Here’s a link to a help video from Hostgator:
http://www.hostgator.com/tutorials/cpanel/hgx3/setting-up-an-addon-domain.htm
Thank you very much WP Ranger.
Unfortunately, when I tried addon domain it said my hosting package does not include this option.
I’d suggest opening a support ticket with Hostgator.
Thank you very much. I have contacted the support team and upgrade my account to be able to use addon domain. Now waiting for them to upgrade my account
