What you want is the voltage between Phase A and B, B & C, A & C for line-to-line voltages. For line to neutral, you'll need a neutral first (usually created from a transformer). You then mesure phase A to neutral, phase B... etc... 3-phase lines usually carry medium to high voltages, are you sure you have enough understanding of what you are doing before toying with 3 phase lines? Seems to me like using an oscilloscope should already be in your reach before approching those lines.
Hello,
Thank you very much for your comment...I'm just going to do a software simulation as we were introduced a circuit simulation software at the school.I asked this because of my curiosity towards 3-phase current.