Apple TV was included for a year last November when I got two new products. I never used it. Now they want me to pay for a subscription. How can I even try it now for a year?

You'll get 3 months free when you buy a new iPhone, iPad, iPod touch, Apple TV, or Mac. Apple TV+ features new Apple Originals every month. All ad‑free and available on demand. And one subscription includes access for up to six family members at no additional cost.

• When does my offer expire?

• You have 90 days after first setting up your device to take advantage of your 3 months free of Apple TV+.

How to cancel a subscription on your iPhone, iPad, or iPod touch

1. Open the Settings app.
2. Tap your name.
3. Tap Subscriptions.
4. 
5. 
   
6. Tap the subscription that you want to manage. Don't see the subscription that you're looking for?
7. Tap Cancel Subscription. (Or if you want to cancel Apple One but keep some subscriptions, tap Choose Individual Services.) If you don’t see Cancel, the subscription is already canceled and won't renew.

It wasn't included automatically, it is an offer that had to be claimed within 3 months of activation and only gets issued on the first qualifying purchase. Users are notified when they activate the device and also when the offer is coming up for expiry. The offer is not valid to those who previously subscribed and once the offer has passed users will only have access to the standard trial.

You can't. That opportunity passed when you didn't activate it with your device.