I want to discontinue my I cloud account and have everything erased how do I do that

This support article explains how to cancel a subscription from Apple on an Apple mobile device, Mac, PC, and online ➔ If you want to cancel a subscription from Apple - Apple Support

Notes:

• You might need to scroll down to find the Cancel Subscription button.

• If you don’t see Cancel Subscription, then the subscription is already canceled and won't renew. An "Expires" date (instead of "Renews") means the current subscription will just run until then. "Resubscribe" is just in case you change your mind about having it end.

• Deleting an app does not cancel a subscription.

• If you don’t cancel trials more than 24 hours before your renewal date, your subscription might renew.

• If you don't have an Apple device, see the options near the bottom of the support document.

• Many subscriptions are set to renew automatically until you intentionally cancel them.

To find out how to remove a payment method, and what to do if you can't remove your last payment method or use no payment method with your Apple ID, read this article --> Remove a payment method from your Apple ID - Apple Support

Ongoing subscriptions and Family Sharing organizers must always have a payment method present. In your case you will have to cancel the subscription and wait until it fully expires before you can remove your card.