@dangerousxxmind if its modern day, every weapon in used... Most commonly guns though.
Fantasy... so its not earth? I suggest making up your own type of knife for this then. I really need more info to help you but since you obviously don't want to give out your story idea (I understand), I'll just give you some generic terms.
Upward slash, downward slash, parry, block (rare), stab, lunge.
Here's a list of the basic techniques https://en.m.wikipedia.org/wiki/Knife_fight