You will need to construct at least 2 surface models to compute volumes. It seems you need to learn a bit more about the software before attempting to use it. I recommend you at least go through the tutorials on surfaces, gradings and corridors. See the Help pull down to access the tutorials.
Neil Wilson (a.k.a. neilw)
AEC Collection/C3D 2024, LDT 2004, Power Civil v8i SS1
WIN 10 64 PRO
http://www.sec-landmgt.com