i want to cancel my apple tv free trial. please help

Cancel the same way as a paid subscription. See instructions in How to cancel a subscription from Apple - Apple Support or use an internet browser to cancel as described in How to cancel Apple TV+ - Apple Support

If you have an iPhone, you can go into the settings and tap on your name, it will take you to your Apple ID. Tap subscriptions, anything you subscribe to is there, and you can cancel there. If don't use iphone and you signed up a different way, I am sure there is a way to cancel your subscription that can be found in the links the other poster shared.

How do you watch Apple TV, and then it would be easier for users to guide you around the interface. I suspect that you can open the iTunes app and cancel Apple TV there. I use PC Windows products and watch Apple TV on a Samsung smart TV, but the more information you provide, the more people can guide you through the process.