How do I find Hulu on Apple TV?

Unlikely the Apple TV is a first generation. As said it was from 2007. Its likely an Apple TV HD (4th gen)

Content on an Apple TV however is not dependent on purchase location, but on logged in account and geographical location determined by IP.

Even if you could get the App, Hulu would not stream outside the U.S. That's a Hulu limitation, not really an Apple TV one.

You can still get any content available in your region normally however.

On 2nd and 3rd generation Apple TVs its a preloaded channel and can be found by looking for the green icon that says Hulu. Make sure its not hidden in Settings->Menu.

On 4th generation and 4K Apple TVs, you download the new Hulu app from the App Store.

It would probably be a 4th gen. The 1st gen was released back in 2007.

Hulu is not available outside of the US. In order to have a US account you would need to have a separate ID for that location, signing up with a valid address and credit card.