Hello jokeryid,
Congratulations on the new iPhone 11! I understand that when setting up your new iPhone, you're asked to enter the password for an email address previously used as an Apple ID. I would be happy to help provide steps to take next so you can finish setting up and enjoying your device.
When you stopped using this email address for your Apple ID, did you change the email address on your account to a new one, or did you create a new Apple ID to use? If you just changed the email address on your account, you may want to try the steps under the "Change your Apple ID temporarily" section here:
If iCloud asks for the password to your previous Apple ID - Apple Support
If you created a new Apple ID with a different email address to use, and you're restoring the iPhone 11 from a backup, you would need to sign in to this old account in order to restore apps and purchases that were made under it. If you need help resetting the password used with this Apple ID, follow the steps here:
If you forgot your Apple ID password - Apple Support
If the iPhone 11 was restored from a backup and you're not able to sign in to the Apple ID shown in the alert, does all of the data appear to have been restored to your device? If so, let's go to Settings > [your name] > iCloud > iCloud Backup. If you see a Stop Restoring iPhone option, tap that to cancel the restore from continuing. This should stop the prompt asking you to sign in to a previous Apple ID to restore purchases.
Let us know what happens after trying those steps.
Cheers!