The kerbal will ask you for certain aspects of your spacecraft. These are their meanings: DeltaV: a measurement of how much change in velocity a craft can make. Isp: Also known as specific impulse, this is a measurement of how efficient an engine is; for multiple engines, please refer yourself to http://wiki.kerbalspaceprogram.com/wiki/Cheat_sheet#Combined_specific_impulse_.28Isp.29 for info. Empty Mass: This is the mass of the rocket minus the fuel being used by the engine(s). Full Mass: The mass of the rocket including the mass of the fuel being used by the engine(s).
The full and empty masses can be in any unit of measurement you desire, so long as they're both in the same unit of measurement. Also, with decouplers, make sure their mass and the mass of what is attatched to them isn't included in the full and empty masses. And the DeltaV is given in meters per second. One more thing: Kerbal Space Program is owned by Squad. Now get out there and BUY IT! https://kerbalspaceprogram.com/kspstore/
