How do I restore the iTunes app and the App Store app on my iPhone 6s
My iPhone 6s no longer has the App Store app or the iTunes app. I think it could be related to my trying to unlock an older phone that I forgot the code to and then tried to unlock using I-tunes.
How do I restore those 2 apps without doing damage to the rest of what is on the iPhone?
iPhone 6s, iOS 11.1