Addressing common Apache install errors on the How to Set Up Apache and PHP which I did awhile back.
For a start make sure that we have the configuration files correct.
Check the File access for
Check for File permissions
4 – Read
2 – Write
1 – Execute
Folders should be 755 and files should be 644.
Correcting myself on the video – to add a user to a group use the folllowing command.
sudo adduser username grouptoadd