Sit on or stand over your bike with one foot firmly on the ground. Find the U-shaped side of the pedal, then slide the ball of your foot down while dropping your heel until you hear a click.
Wiggle your foot to make sure the cleat's secure, then repeat the above steps to clip in with your other shoe. Below is a helpful video for clipping in!
With your hand on the Torq Knob to keep the pedals stationary, swing your heel away from the bike to disengage the cleat from the pedal.