R6 inverse kinematics animations?

I know this is not a request site, though I need some help. Now I am new so I shouldn't really be doing 'advanced' stuff like this but, I need an animation system similar to soulshatters, or criminality, but I don't know how to use Inverse kinematics, etc. If someone could put it in simple terms that would be great (or give me the script, but i prefer learning).