Come on man...
Try the noise gate. Play around with it. There are NO settings that will work universally with a noise gate or any other processor. A noise gate will block out sound below a certain level, and let sound through at a certain level. Great for eliminating that hum from a guitar amp, background noise in a vocal.
Read up on what these things do. Understand what a noise gate is. Once you get the fundamentals, the rest will follow. Experiment, have fun with it.
Don't mean to sound harsh, but you really should just try it, and form your own understanding of how things work.
Emeric