I have done yoga. The first time i was quite overwhelm as i felt I could not do any of the poses that everyone was doing. After the first session, i felt quite relaxed and stretched, after reviewing the session, I had not realised that i was doing poses that i thought i could not do.
My yoga instructor was a colleague and she was really good. She had shown us the poses and then saw us beginner, intermediate and advance level of the pose -so that we could feel it.
Learning how to relax by controlling my breathing was difficult at first.