How do I cancel itunes ? I never use them. Please help.

If you have recurring charges that are billed through Apple, see instructions in How to cancel a subscription from Apple - Apple Support and if necessary also see If the subscription that you want to cancel is not listed - Apple Support including the following:

If you still can't find the subscription and cancel it, contact Apple Support.

The iTunes app is free.

As mentioned above, some related Apple services can have subscriptions with recurring charges, such as Apple Music.

But the iTunes app itself is used for other purposes, including syncing your iPhone with Windows and older versions of Mac, and there are no charges for that usage.