Was that a "yum update" command?
In that case those are all packages you already have on the system that are outdated and can be upgraded. And if you're using Gnome you can get cool backgrounds from gnome's website
. You'll also find some in the "Desktop settings" somewhere in the menus.
What soundcard do you have? Did the "Soundcard Detection" from the system settings menu give no sound? I think you might need a driver or something. Or make sure you have alsa installed (Advanced Linux Sound Architecture).