Assuming you dont want to overclock it, you shouldn't touch it.
If you do want to overclock it I can tell you probably should go and look up a bit more about it If you dont theres a good chance your going to do some damage to your card.
This GTX 980 overclocking tutorial will walk through how to overclock nVidia's Maxwell architecture, explain power target %, voltage, memory clock, and more. - All Pages