My apple id is not signing in to the AppStore in my iPhone 6

when i bought my iphone it was just fine and working with my new apple id but after 4 days when i try to download any app form the appstore the circle keeps spinning and then it goes back to "get" it asks for my password and i enter it right so i tried to logout and relog but i cant login again whenever i press login nothing happens and also i tried a former apple id of mine it does the same thing although my apple id is working properly on iCloud and i reloged from i cloud but the AppStore is not working and this problem seems to be in my iPhone as when i tried another apple id it didnt work so please if anybody got a solution here please tell me what to do.

Thanks.