New WP installation on Hostgator domain but not working

If you followed the process here, then it’s really down to hostgator to see you right and work with you to remedy, given it’s offered as a one-click install option through their cpanel.

That said, i’d be inclined to the follow what’s said here first.

https://www.hostgator.com/help/article/error-messages-during-one-click-wordpress-install

And if you’re still getting nowhere trying again with the auto install method, then i’d be thinking about doing it the hands on way, manually.

Your host offers instructions for doing this.
https://www.hostgator.com/help/article/how-to-install-wordpress-manually