I just want to cancel my YouTube membership..

Go to Settings/[your name]/Subscriptions. Do you see the Youtube subscription? If you do tap on it and tap Cancel. if there is no Cancel button and just renew options it has been canceled, but the current subscription is already paid for, so it will be active until the end of the subscription period.

If you don’t see a subscription for Youtube on the phone perhaps you subscribed directly with Youtube. In that case go to https://youtube.com and cancel it there.

No one here can cancel it for you. All we can do is point you in the right direction.

How you cancel depends on how you signed up. If you signed up via the iOS app then it appears as a subscription in your App Store account, and you can cancel it there (Settings -> iCloud -> Subscriptions).

If you signed up via YouTube's site, you need to cancel it there.

All this is documented on YouTube's "how do I cancel' page at https://support.google.com/youtube/answer/6308278?hl=en&co=GENIE.Platform%3DAndroid#zippy=%2Ccancel-your-paid-membership