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. Your strong-side leg can be slightly behind the weak-side leg.
Keep your shoulders squared with the target.
Grasp the handgun using opposite pressure with both hands.
Lock the shooting arm forward while keeping the support arm bent with the elbow close to the body and pointing down.