Here are a collection of simple WebGPU examples. They should work in the latest WebKit builds and Safari Technology Preview release. The full specification is a work-in-progress on GitHub, and the implementation may differ from the current API.
Make sure you are on a system with WebGPU enabled. In Safari, first make sure the Developer Menu is visible (Preferences > Advanced), then ensure Develop > Experimental Features > WebGPU is checked.
WebGPU is an experimental technology, and you should not browse the entire Web with it enabled for now. It doesn't do much validation of content, and thus may cause some issues with your computer.