how to get itunes back on iPad 7th generation, 14

The iTunes application does not and has never existed on an iPad. You cannot get back what it never had.

The iPad has the iTunes Store app and the Music App. The Music App was previously known as the iPod app until iOS 5 when it was changed to the Music App.

What exactly are you trying to accomplish?

iTunes, as an iOS/iPadOS App, has been replaced by the Music App. The Apple Music App provides very similar functionality.