Account

Note the restrictions in the article.

Apple ID Name Change. https://support.apple.com/en-us/HT202667

 What to do after you change your Apple ID or password - Apple Support     https://support.apple.com/en-us/HT204071 I suggest doing this before you change your Apple ID or password.

You can also add 2 Factor Authentication to your account for more security.

Apple ID -Two-factor authentication https://support.apple.com/en-us/HT204915

 Two Factor Authentification availability. https://support.apple.com/en-us/HT205075

 Apple ID - Using app-specific passwords. https://support.apple.com/en-us/HT204397

Apple ID - Two Step Verifications FAQ https://support.apple.com/en-us/HT204152