What kind of clipless pedals are they? Some have a bit more of a learning curve than others. If they are Shimano SPD style double sided pedals, you will pick it up very fast. Single sided road pedals (Look style) are a little trickier as occasionally you have to kick the pedal over to engage the cleat. Trying them out on a bike than can coast seems good advice. If you have a trainer, I would consider even putting the bike on it for a test run.
Either way, I find clipless much easier and safer than my old clips and straps. I know there are many fans of straps here, though, so YMMV.
Good luck.