The idea is simple. Using ssh you can login and run commands on your wifi connected Raspberry Pi. In the image below I use a simple USB soundcard that I have connected to my amplifier. From the terminal you then play music with mplayer and change some of the volume with alsamixer. Choosing Raspbian from NOOBS works just fine.
To get the usb soundcard selected at boot then edit /etc/modprobe.d/alsa-base.conf with
options snd-usb-audio index=0
options snd_bcm2835 index=1
Information taken from raspberrypi.stackexchange.com
I think this is an excellent opportunity to have some fun and learn a little Linux.