NEED HELP PLAYING DVDS ON UBUNTU COMPUTER PLEASE

Hi guys! My brother sent me a Macbook Pro that he's put Ubuntu on ( he doesn't know which version for sure, but he thinks it's the latest version). I am used to Peppermint so it took me a bit of looking around to find out how to add new software ( in Peppermint it's via the software manager). it took less than 5 mins to install VLC. It all looks fine ( I have that on my Peppermint netbook) but I cannot figure out how to play a DVD from the external DVD player I have. I admit I had trouble figuring it out...