Clipping in and out of clipless pedals:
When clipping into the pedal, you are pushing the cleat into the pedal body and allowing the back of the cleat (the spring) to snap over the rear of the cleat. Begin by flipping the pedal over with your toe, and in one movement push forward and down with your foot into the pedal. You’ll feel the spring at the rear of the pedals snap over the cleat.
When clipping out, twist your foot on the ball of your foot, moving your ankle away from the crank arm. On the right foot, twist ankle right, and on left, twist ankle left.
It’s simply a matter of practice. Find a safe place to do it.