Holding the PickStudy these illustrations for a moment:
Curve your index finger. Lay the pick on the first finger joint. Press down with your thumb. There you have it. The pick is held by the thumb pressing against the side of the first finger.
However, notice how the remaining fingers are relaxed and uncurled. There is no reason to make your hand into a fist just to hold a pick. Doing so will make your hand muscle bound. Your playing will be clumsy and your hand will tire quickly.
When you are comfortable with holding the guitar and the pick you are ready for the
next lesson.