Multiple iPads & phone connected
I purchased a new iPad, have kept the old one for my granddaughter to use. How do I disconnect the old iPad from my email, messaging and texts that I receive on my new iPad and phone?
iPad, iPadOS 14
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
Having transferred your data, you can prepare your old iPad properly for reuse - as this will ensure that the Activation Lock associated with the original AppleID is removed, along with all data and other sensitive information:
What to do before you sell, give away or trade in your iPhone, iPad or iPod touch – Apple Support