publish a web on server

Hi all.
I'm very new developing web.
I have access to a running web server that have running web pages. i want to add there my fist one, a simple hello world web page.
in the server, in c:\app\web\ are the folder for the running pages.
something like c:\app\web\runpage1 and can be access by http://servername/runpage1/pagename.aspx

I copy there the folder for my web page but wen i try the http://servername/HelloWorld/Default.aspx nothing happens.
what i don't know about copying the files/folder for a new page to a server?