Apple Watch Apps Don't Load
Not sure if you're still having this issue and this is also for future users who have the same problem as well. A lot of people experience the app not loading problem. 

The solution to this is fairly easy. All you have to do is restart your Apple Watch. You can do so by pressing on the side buttons (Digital Crown and the button below it) at once. Just wait for it to restart. If it doesn't help, reset it into factory settings.

Source: Cupertino Watch