The flute rests on the lowest section of your left hand's index finger. This part of the finger meets the underside of the flute body between the two topmost keys. The finger curves around the flute a bit, like a question mark, before resting on the key. The hand will turn slightly counter-clockwise to face towards the right, or down the flute, which will make it easier to reach the other keys. Stretch them out until they rest on the other keys and your pinky can easily reach its key if necessary. The third finger will almost, but not quite straighten.