Q: c

Hey Rebecca,

After changing your Apple ID there are a number of different places you need to enter the new information on your various devices. This article provides a list - What to do after you change your Apple ID email address or password - Apple Support

If, rather than changing the Apple ID you actually created a new Apple ID and intend to use that, use the steps in this article - Sign in with a different Apple ID on your iPhone, iPad, or iPod touch - Apple Support

Thanks for using Apple Support Communities.

Happy computing.