Problem in Unity and MRTK Project (FPS Stimulator)

I am Working On a Project That is Based On FPS (First Person Shooting) Stimulator, Where the Gun is Real and all Other Scenario is Virtual (Augmented). I am Having Trouble with Object Detection and Making This all Work Together as I am New to Hololens, Unity, and MRTK environment. The Firing Needs to Be Triggered when we Close our Index finger after the gun is detected. And After Each Fire, We Need to Update the Scoreboard.