How to get iTunes on a iPad Pro

Use App Library to search the Music app. 

See this Apple article: Use the App Library and Home Screen to organize your iPad apps

https://support.apple.com/en-us/HT212717

You have quick access to App Library by tapping the App Library icon in the iPad's Dock.

iTunes is an app that can work on a Windows PC or on old Macs.

iTunes Store is a built-in app that comes along with iOS/iPadOS on iPhones & iPads.

Regards

Giulio