You have received some good advice.
IMHO the "Mozambique drill" is obsolete. You should not shoot 2 and assess your target, do not get into that habit. You should constantly assess and adjust fire accordingly. if faced with multiple bad guys you may need to put one or two on each one and then come back, but that is not the same thing.
Congratulations on deciding to carry. Now the hard part ask yourself this question; " Am I willing to kill another person to save myself or my family?" If the answer is no, do not carry.
My rifle and pistol are tools, I am the weapon.