Cannot activate 5S
So i’m trying to activate my first ever iPhone. It seemed to be going well until it said “your iPhone was updated successfully. There are just a few more steps to follow, and then you’re done!”. It will either use wifi and then tell me that the activation server cannot be reached, or if I launch iTunes it will repeatedly show the home screen then flash back to a white screen with the iTunes logo in the center. It does this over and over again. Help!