I was setting up a LAMP server for personal use yesterday, and my php files just loaded up a white page. I fiddled around in the php.ini and I got it to load text, but that text was an error.

Warning: Unknown: failed to open stream: Permission denied in Unknown on line 0 Fatal error: Unknown: Failed opening required '/var/www/index.php' (include_path='.:/usr/share/php:/usr/share/pear') in Unknown on line 0
I don't know what it means, and I don't have a /usr/share/pear folder. I did some googling and that didn't turn up anything helpful. How can I fix this?