Also not in the core mission? Playing DVDs restricted by commercial digital rights management software, which includes just about every DVD you want to watch. Ubuntu makes a package available to read the structure of a DVD, and even installs a script to implement a famous de-crypting system for actually watching them, but relies on you to manually trigger it. So be it. Head to the Applications menu again, hover over Accessories, then select Terminal. Enter this line:
sudo apt-get install libdvdread4 sudo /usr/share/doc/libdvdread4/install-css.sh
sudo apt-get install libdvdread4 && sudo /usr/share/doc/libdvdread4/install-css.sh
You'll be prompted to type in the password you gave when installing, unless you're running off the thumb drive. Do so, and you'll have full DVD reading and playing access.
At this point, you can explore most of the web and access most of your media without problems. You could learn how app installation works on your own, and gradually poke around to fix the things you'd like to change, but who has time for that? Open Firefox from the icon right next to your upper-left menus. Head to the web site of Ubuntu Tweak. Click the "Download Now" button on the front page, keep the "Open with" selection, and hit "Install Package" in the app window that pops up. Head to your Applications menu, head down to the new System Tools entry, and select Ubuntu Tweak.
Inside Ubuntu Tweak, there are many worthy sub-sections that make life a lot easier in a new Ubuntu. The Application Center provides lots of popular and neat third-party applications (pretty much any application you're looking for, really) as one-click installs. Also worth peeking at are Desktop Icon Settings, Advanced Power Manager, and, especially, Window Manager Settings, where you can re-arrange the newly Mac-like, left-hand window button controls if you simply do not like them.
Now that you're set up with some basics, you can learn how the rest of the system works over time, knowing that your complete Van Halen collection, your West Wing DVDs, and Google Earth are all accessible, should you need comforting when the answers seem hazy.