I want to download iTunes to my iPad mini

iTunes is a program for PC or Mac (it cannot run on an iPhone/iPad).

If you're talking about iTunes Store, check better in different screen pages and/or into folders.

If it's not there, you might have restrictions on your ScreenTime. Go to:

Settings>Screen Time>Content&Privacy Restrictions>Allowed Apps... Itunes Store must be enabled.

or

redownload it from App Store.

Regards

Giulio