problem installing wp on debian linux localhost

Hi all

I am tying to install wp on my linux box. It is a very straightforward desktop system running iceweasel browser and open office.

I just want a local install (what I think is http://localhost)
I looked on a few web pages and installed LAMP and got all that working ok – did the test and when I put http://localhost in the url the browser window displays the words:
‘It works!
This is the default web page for this server.

The web server software is running but no content has been added, yet.’

So far so good.

I then downloaded the WP package using the debian package manager and it installed it to usr/share/wordpress

I looked at the 5 minute install but none of that works for me sorry, I have probably missed something.

I presume I need to tell the apache2 thing where wordpress is do I?
I went to etc/apache2/sites-enabled and found 000-default which I edited to say DocumentRoot usr/share/wordpress
and

<Directory /var/www/>

the rest of the file I left alone.

if I put http://localhost/wordpress/ as the url it says

‘Not Found

The requested URL /wordpress/ was not found on this server.’

Which files would need to be changed?

Thanks very much for any help you can give.