Install your USB 3.0 cables (denoted with a blue-colored end) into any available slots on the board, making sure to line up the pins with the holes in the USB 3.0 cables.
It’s also a good time to plug in your USB 3.0 header, USB 2.0 header, and audio passthrough. Audio is located on the bottom left of most motherboards. It will be labeled, and the pinouts will be different to the USB 2.0 headers. Install your USB 3.0 cables (denoted with a blue-colored end) into any available slots on the board, making sure to line up the pins with the holes in the USB 3.0 cables.