I'm building a computer and I just got an antec three hundred two with an asrock 970DE3. However on the case there's an USB 3.0 wire by the HDa cable and I can't find anywhere to plug the USB 3.0 cable? Are they compatible? I'm completely new at this. Also I heard that if there isn't a place to plug my usb 3.0 cable then I should just leave it alone. Not sure if that's okay. And also my fans on the case are 3 pin and the motherboard is 4 pin. Should I but adapters for the 3.0 USB and the 3 pin fans?