how to change email for app store for my new ipad
I would like to change my email to the app store when trying to download an app. There is a default email but I am unable to change the email that is on file. Thanks. Su
Your email address is your AppleID - and unless this falls within a very limited scope of addresses that cannot be changed, you should be able to change your associated email (and by definition, your AppleID).
This Apple help page should help you:
https://support.apple.com/en-gb/HT202667
You can, however, use a different AppleID for the App Store - but you should carefully research and consider the implications of doing so.
Hope this may of been some help to you.