I’m trying to change my email

Do you mean that you want to change the email that you use as your Apple ID? If so, see: Change your Apple ID - Apple Support

and be sure to note the following from that link:

Before you change your Apple ID

Sign out of all Apple services and devices that use your Apple ID. If you want to use your iPhone, iPad, or iPod touch to change your Apple ID, stay signed in with your Apple ID on only that device.

If you mean your contact email for the Support Communities, they use your Apple ID email address.

If your Apple ID email address is disconnected, I suggest you change that to a working email address so you can receive notifications such as a password reset when required.

Your Apple ID email address?

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.