There are a few resources that can provide you with some excellent guidance.

The WebWorldWind website itself, especially the Examples webpage,

The WorldWind forum where the world community asks questions and provides each other with answers,

All of these resources are generously provided by the larger World Wind community. We look forward to your participation in advancing this foundational technology for spatial data.

Instead of building an app from scratch, are there other World Wind apps you can build on? Yes, any World Wind app will do! And these are there for you as open source: