1) You need to do that in the BIOS. You should have fan speed controls there.
2) The default fan curves are based on the temperature of the liquid coolant. In your image, that's at 26.3C, so you'd have a ways to go before the fans started kicking up. This is by design and it's the appropriate temperature for your radiators fans so don't go creating a custom fan curve based on CPU temp! If you do want to create a custom fan curve, leave the control variable to the H100i V2 temperature and you'll probably want to have the curve between 30-40/45C.