World Machine tutorials are scarce these days, but what you’re attempting is simple enough.
Create “Scene view” device as an output. Plug in your heightmap/mesh, material/texture/colormap, and “water” data into it. Then “lock preview” on that scene view device. Now editing your graph, you’ll get realtime update of those three properly set up. You can find a few Scene view screenshots straight from WM 3D view within my earlier WIP forum post.