You should go to:
Members area,
Login,
Select in Action GoTo Cpanel and then:
You should configure your FTP servers, upload an index.html or index.php file and put your main information there.
EDIT:
You should upload everything to your public_html folder always, you should see a file that should say do_not_upload_here before that folder.
Public html is what what it sounds like. The html container folder that contains what will be visible*. (*VERY rough explanation)
You can use their file manager or an FTP client for this pourpose.
BTW beware of the affiliate programe fo 000webhost, check it out, total hoax (the web hosting is very good for being free).
I´ll gladly expand if you have any doubts.
Here is a good FTP basic tutorial:
http://www.youtube.com/watch?v=I85sldEvLuY&feature=related