Nginx information badly needed

First I must say I no nothing of Ruby or nginx or even if I have Ruby,
having said that I have downloaded nginx to the bit that get to welcome
to nginx which apart from stopping and starting is as far as the
download went. I do not know how to upload a website to nginx and when I
click on the 50x.html icon that is in /var/www/ I get the unavailable.

file:///var/www/nginx-default/50x.html

The page you are looking for is temporarily unavailable.
Please try again later.

Is this the page where the website will be?

Would appreciate any help.