How you stand must be a repeatable action, exactly the same every time. But there are a few different ways to plant your feet and achieve that.
There are three different stances an archery can use. Here are their advantages and disadvantages:
This stance is easy for new archers to get to grips with and is used by some of the world's best. Your feet should be in line with each other so that if a line is drawn from your toes, it would go straight to the target. The benefit to this stance is that your shoulders are in line and pointing towards the target, making for an easy, repeatable action.
The open stance gives you the greatest stable platform to shoot from by moving your rear foot forwards. You must however rotate your abdomen and make sure your hips follow your feet.
The closed stance is used if you are having problems aligning your shoulders. This is done by moving your rear foot backwards, though it can lead to clearance issues.
Remember, your weight should be on the balls of your feet, slightly tipped forward. A good tip is to press your toes into the ground.