Probably as a new user, you are queries about some very initial operation about ZW3D, here are some youtube videos that can be helpful
Modeling workflow: https://www.youtube.com/watch?v=oeKTvD8x3E4
User Interface: https://www.youtube.com/watch?v=kdUnGQZ7FL0
Mouse Control: https://www.youtube.com/watch?v=LjqcPAmVlKM
