Change in apple id

If you change the email address, you retain access to all your data and purchases. Note the restrictions in the article.

Apple ID Name Change.        

 What to do after you change your Apple ID or password - Apple Support    I suggest doing this before you change your Apple ID or password.

If you create/use a new Apple ID, you will lose access to some of your data and the purchases made with your existing Apple ID. 

Welcome to the Apple community.

Do you mean to change to another Apple ID or do you mean to change the email address that you use with your Apple ID?