White screen on itunes store and devices on itunes?!

Just got a new iphone 5 for christmas and carnt use it to its full potential as itunes wont work. The itunes store wont work and just comes up with a black screen sayin itunes store and when i plug my devices in, the iphone does nothing and come up with a white screen saying iphone and my ipad tryes to back up which i want it to do but just says its loading on the top bar. Can some one please help as soon as possible please? As theres so many diffrent things on the support page ive tryed a few but non have worked.

Thanks Matt.