Backup restore

These support pages should get you started with setup of your new iPad - and the methods of transferring your data from old to new iPad:

Set up your iPhone, iPad or iPod touch – Apple Support

Transfer data from your previous iOS device to your new iPhone, iPad, or iPod touch - Apple Support

Use Quick Start to transfer data to a new iPhone, iPad or iPod touch – Apple Support

If the donor iPad, from which you are transferring your data precedes iOS12.4, QuickStart will not be available.

“Transfer” is rather a misnomer. In reality, your data and setup is merely cloned to the new device. Nothing is moved or removed from the original device.

An alternative is to restore either an iCloud or iTunes backup to the new device:

How to back up your iPhone, iPad and iPod touch – Apple Support

Restore your iPhone, iPad, or iPod touch from a backup - Apple Support

See https://support.apple.com/guide/icloud/restore-or-set-up-your-ios-or-ipados-device-mm7e756df7fd/icloud

If you have already started the setup of the new iPad and passed the step where it asks about transferring, press the home button below the screen on your iPad (or swipe up from the bottom of the screen on newer iPad Pros / latest iPad Air), and choose Start Over.

If the setup already finished without restoring your backup, go to the Home Screen, then go to Settings > General > Reset > Erase All Content and Settings. Follow the prompts, let it erase, then do the setup again as per the link I put above.