Linux Noob in Dire Need of Help

So long story short, I'm using my Xubuntu 12.04 backup PC for a few days while I wait on my new graphics card, my main PC doesn't have onboard graphics. I am trying to install mumble, and I am totally lost. Pls help.

Xubuntu has packaged synapse for installing stuff

I use ubuntu but if you need to install something first off is it compatible for Linux and if it installed the setup I usually use the terminal I think sudo apt-get install (the name of program) . I;m not sure exactly how to help but try.

I got it (: