Hello Tarte TinTin,
The concern with creating a new email for your Apple ID is that any purchase made with the original Apple ID would not be available.
With that in mind, perhaps creating an alias would provide what you are looking for:
Create an email alias
1. In Mail on iCloud.com, click
at the top of the Mailboxes list, then choose Preferences.
2. Click Accounts, then click “Add an alias.”
3. Provide the requested information:
• Alias: The text you provide becomes the email address (alias@icloud.com). An alias must contain between 3 and 20 characters.
• Full Name: The name you provide appears in the From field of the messages you send.
Label: Aliases are listed alphabetically by label.
4. Click Add, then click Done.
This would allow you to create an email that you used for a specific purpose, like for your Apple ID, without having to actually change your Apple ID.
Have a good day.