I am just installing a local Ubuntu 14.04 server fresh with a view to running Joomla for testing. I have been following these instructions
https://help.ubuntu.com/community/Joomla

When I use a browser to access the server name I get the Apache confirmation page so that is good. However when I use http://servername/joomla I get a 404. Not sure what I have not done.

In the user guide I did not do the following because I did not know how or what it meant (joomla database section) " You will need to chose the yourusername and yourpassword. If the command was successful, activate the new permissions: " I guess this could be related but they do not spell it out so .... hey ... I have no idea but it has to be real obvious.

Any ideas please?

Start with the log files. Apache maintains an access log and an error log; their locations are in the Apache config file (I don't know where this is on Ubuntu, perhaps /etc/httpd.d or similar).

Joomla, which I can't help you with, might have log files as well. Figure out where they are and check them.

I can define the problem more clearly after experimenting a bit ....

In /var/www/ there are two directories - html and joomla. The html directory is used by Apache to store the message you see to know that Apache is good.

I renamed the html directory and then named the joomla directory html. The joomla installer would then launch. So I conclude that the name of the joomla directory needs to be included in some configuration file but I do not know which .....

ok ... solved it. This is how ...

In Apache the default Virtual Server has a Document Root set to /var/www/html. Modify to /var/www/ only and the joomla installation directory will then be accessible and the installer run.