Geometry node assistant

How do you guys know which node goes with what I been learning about nodes and what they do and when I try to make something it doesn’t come out right

Geometry Nodes PDF Manual
https://www.blendernation.com/2022/01/16/extensive-blender-geometry-nodes-manual/

Geometry Nodes
http://blender-3d.338.s1.nabble.com/Geometry-Nodes-tp1661.html

Geometry Nodes _ Generators
http://blender-3d.338.s1.nabble.com/Geometry-nodes-Generators-tp1790.html

i would recommend watching some basic beginner yt tutorials about GN. e.g. from Erindale

also just3dthings and crossmindstudio