Changing the email address that identifies your AppleID is straightforward. You don’t need to lose any data.
An AppleID account is intended to be for life, with its owner updating core information (such as primary, secondary email address - and trusted phone numbers) as necessary.
Change your Apple ID - Apple Support
What to do after you change your Apple ID or password - Apple Support
Be aware that if you do fully erase your iPad - and setup from new with a new AppleID account - you will permanently lose access to any Apps, media and subscriptions that are associated with your current AppleID. App, media and subscription purchases are forever associated with the AppleID account from which they were purchased - and are not transferable.