App Store Download Problem

Ok so I have a Ipod 5th generation. I was on my app store and I tapped Get (the button you push when you download an app) and after I typed in my password to allow the download I waited a few seconds then it completely stopped downloading and the Get button re-appeared again. So I restarted my ipod quite a few times, still didnt work. Then I signed out and tried signing back in, and now thats not allowing me to sign into my own itunes account! Help me please!