WHy am I paying for Hulu, Disney plus and other apps if I have APPLE TV

The apps are separate from the services. You are not paying for these content provider apps. You are paying for the chosen subscription services (“content”).

If you have the Apple TV box, then which model?

Identify your Apple TV model - Apple Support

Find your Apple TV model number - Apple Support

The Apple TV physical device that connects to your TV (e.g., Buy Apple TV 4K - Apple ) has Hule and Disney Plus apps but you still need a Hulu and Disney subscription to watch those.

No.

The Apple TV hardware does not include subscriptions to streaming services.

You have to pay for content.