by Carlos Barrios.
Thank you David for your reply. I am no t sure if I understood you, but I did created a test html file for checking if the web server is right pointed to the www-data folder and I could see the web page well. The test file was located at the same level of the index.php.
Sorry if I misunderstand you, but I have not experience in this kind of installation. I have installed Moodle before, but using Fantastico app in Hosted web servers.