If you go to the EFS page in your GOG library, you should be able to access both the classic manual and the revised tutorial. Let me know if you do not find it there.

Also, feel free to check out this playlist for insights on playing the game: https://www.youtube.com/playlist?list=PLxou4k4H1Y_xJjbhonbCVnGgJZGTnC6if