Thanks for buying the tool!
When you enter the Mesh Edit mode, you can select vertices with the right mouse button and transform them using the keyboard shortcuts G (to translate), R (to rotate) and S (to scale). You can also extrude selected faces into new geometry with E.
Switching from vert select to face select mode will make it easier to select faces you want to extrude.
Hope that helps, the full shortcut guide comes with the package, it has more shortcuts listed as well.