Perhaps the easiest method of transferring data from one iPad to another is to start by properly wiping the destination iPad - and setting-up again as a new iPad. Using this process you can use your old iPad as the source. This procedure is likely to be the simplest method to completely wipe the iPad and start again:
What to do before you sell, give away or trade in your iPhone, iPad or iPod touch – Apple Support
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