For learning a beginning one foot glide, you really don't need to worry about a low knee bend. That will come later, w/ other skills.
Mainly you need to learn to commit all your weight over the skating foot, as others have said. We say, "shift and lift" to remind people that you have to shift your weight *before* you pick up the foot. Try it on land--if you just were going to stand on one foot, you will unconsciously shift your weight over before lifting. On the ice, sometimes you have to consciously do it--and it's going to feel like you're leaning over, when really you've just moved over the skating side. It also helps to start w/ a 2 foot glide w/ your feet very close together, then pick the one foot straight up.