Once you can comfortably sit/stand with your feet spread about 1.5 times the distance between your shoulders, bend your knees sufficiently to place them directly above the balls of your feet, and hold that position for half a minute or so, it's time to begin playing around with variations on the theme.
The first and most important variation is about whether your weight is equally distributed on both feet or supported primarily by one foot.
To begin with, simple move your body gently in a sideways rocking motion, left-right-left-right. Take your time with this, and pay attention to how it feels in your feet, ankles, calves, knees, thighs, hips, buttocks, lower back, and belly. Practice for a short time, whenever you can, being careful not to overtire ANY of these links in the chain.
Start with your feet fairly close together (a high stance) and your toes pointed outward at about 30 to 45 degrees, then move your feet further apart (a lower stance) as your muscles begin to warm up and loosen up. Finish off by moving your feet closer together again.
For now it's enough to move 10% of your weight back and forth, so you move from placing 60% of your weight on one foot to placing 60% of your weight on the other. (If the math doesn't seem to work out, remember that equal distribution is 50% on each foot.)
When you are ready to go further, you can move more of your weight back and forth, deepen your stance (move your feet further apart), and spend more time in lower stances.
As before, it's best to have something soft in front of you in case you need an escape route.
That's enough for one lesson.