I don't know much about computers. But a friend of mine installed Ubuntu 14.04 to try and I like it. But I can't play videos and music. Its says it needs MP3 codecs. How can I get them?
Open a terminal Ctrl+Alt+T. Then type the following command (or copy-paste it):
sudo apt-get install ubuntu-restricted-extras
This command will ask for your password. Note that when entering the password, you won't see anything printed in the terminal, neither letters, nor stars. Just enter it and hit Enter.
Afterwards the restricted codecs should be installed. I wonder why your friend didn't install them during setup.