bhagi108, I wouldn't return the shoes or pedals. I waited a while before buying clipless, and even though I had a bad fall I don't regret it. It's much easier pedaling. With the toe clips and running shoes that I used to use, I was constantly worrying about foot placement and my shoes used to rub against the pedal making this really annoying squeaking sound.

I would say just practice a lot in a hallway or doorway first, letting yourself tip and losing your balance and then unclipping. This way it becomes muscle memory. Also keep the tension loose on the clips, and when you do first take them out unclip well before any anticipated stops. Of course, the main reason for falling is the unanticipated stops and you really can't do much about those.