2
Position the bar behind your head, with the weight on your back shoulders. Place your shoulders below the bar for it to be across the back of your shoulders. You will want the bar to be positioned over your trapezius muscles, not on your neck. Grasp the bar with your hands at a spot that you find comfortable, usually about six inches (15cm) outward from your shoulders. If this is your first time squatting, do this with no weight on the bar to learn the movement first.
Raise and dismount the barbell from the rack. Then take a step forward or backward, or the rack would interfere in the motion.
You should always have a spotter when squatting! This is especially important when "racking" (taking weights on and off the rack).