$9.99 is the price of Apple TV+ in Australia (after the trial). Do you have an Australian Apple ID account?
This subscription allows you to watch any show from the Apple TV+ catalog. There are also shows in the Apple TV app that are not included in Apple TV+. Those other shows will have to be paid for separately, if you want to watch any of that (other subscriptions). What were you trying to watch exactly?
About Apple TV+ - Apple
Apple Originals - Apple TV+ Press
List of Apple TV+ original programming (episodic/series) - Wikipedia
List of Apple TV+ original films - Wikipedia
On iPad or iPhone, you are normally always signed in with your Apple ID account, and then you should be able to watch the subscription content.
On Mac, you will have to additionally sign in to the TV app (menu Account).
On the Apple TV box, multiple accounts are possible. Verify that the wanted account is switched as the active one.
On browsers, sign in to the site through the Sign In button in the top-right corner.
On third party devices with the Apple TV app (including select smart TVs), users will have to sign in to the app, through the in-app Settings (sprockets wheel icon), with the Apple ID account that has the subscription linked to it. Else the subscription will not be recognized/applied.
