In today’s handgun world, there are two main upright shooting stances—the Isosceles and the Weaver—from which other stances have evolved. While the Weaver is probably better known, the Isosceles is more commonly taught to beginners. From the article "Choosing a Handgun Shooting Stance."
Stand with your feet shoulder width apart with your strong-side leg slightly back in what is often called a boxer’s stance.
Angle your support arm’s shoulder toward the target.
Bend your knees while keeping your body weight slightly forward.
Grasp the gun using opposite pressure with both hands.
Keep both elbows bent with the support elbow pointing downward.