I tried launching the Apple Watch app on iPhone 6

After updating to iOS 8.2, the Apple Watch app was automatically added.

So, I tried starting it right away.

When you start it up, a screen will appear prompting you to start pairing.

Tap the content to watch the promotional video.

If I tap App Store, will I be able to go to the Apple Watch purchase screen from here?

When you start pairing, you will be prompted to point your Apple Watch at the camera.

If you choose manual, you will be prompted to confirm and enter the name of your Apple Watch.

I've included the images above so you can see.