Its much easier to practice clipping in and out outside while moving, clip one foot in (I do my right first) then push off while moving clip in the left. Its okay if you pedal a few times before it actually clicks in. Just be sure to unclip at least one foot before you come to a complete stop. It will become second nature before you know it! I was scared my first time, I've fell a handful of times, but now I'm much more confident and in time so will you! Practice practice practice!!