Nah, it's easy! All you have to do is stop while sitting on the bike. Rest one foot on a rock, tree root or other object and stay clipped in with the other foot. Then begin pedalling with the clipped in foot, regain balance and clip the other foot in.
Just make sure you're in a good gear. Too low will cause you to spin and lose balance. Better to pick a moderate to harder gear to pedal at a slow consistent cadence...