Can't Seem To Change Settings

Bear with me, I'm brand new to Android phones, so I'm feeling very much like a dummy today.

My phone is a Motorola E 3G. When I go into the Settings to change things like the volume, it won't work. The volume is set as high as it goes, and nothing I do will allow me to change it. I am also unable to turn my mobile data off, which means for now I'm keeping the phone off 95% of the time to avoid wasting data.

Help!