how to use split screen on iPad Pro

You may find these overview Apple video guides to be helpful:

After viewing, you’ll be ready for the additional Multitasking Guide:

Use Multitasking on your iPad - Apple Support

The iPad User Guide for iPadOS is also a rich source of information. Here are links to both the downloadable and online versions of the Guide:

https://help.apple.com/epub/ipad/en/

https://support.apple.com/guide/ipad/welcome/ipados

I hope this explanation and additional information is helpful in resolving any difficulties you may be having with Slide Over, Split Screen and Multitasking features of your iPad.

https://support.apple.com/en-us/HT207582

You can use Split View with iPad Pro, iPad (5th generation and later), iPad Air 2 and later, or iPad mini 4 and later.

JDee