Apple TV not allowing me to watch content

Make sure you are signed in. Open the TV application and check the Account drop down menu. If you are signed in you will see your Apple ID account name.

Click on the Apple TV+ tab in the application. This is the content subscribers to Apple TV+ can view. Choose one of them - Ted Lasso is prominent on the Apple TV+ page at the moment, or perhaps choose The Morning Show. You should be able to play any episode of these shows.

The Store tab offers other content to rent or buy and this is from other providers - not Apple..

There are many streaming services available on Apple TV and they all require separate subscriptions: Disney+ won't give you the content for Paramount+ for example.

Your subscription to Apple TV+ will unlock the Apple TV+ collection only and after you have signed in via the TV application on your Mac.

You will be asked for payment for other streaming services if you wish to watch their content.