The forward thrusters rotated by the black knob allow you to steer, and to back off the beach.
Think of them as a bow thruster. Remember that you are driving a hockey puck. Steering with the after fan vanes causes you to skid. For more controlled steering at low speed, the thruster might work better for you.
The leftmost throttle is for the skirt fan. Use it to lift for movement and to sit down to stop on the beach.
The idle position lifts but reduces the flow to the forward thrusters.