Here's a video link that shows exactly what we do for one step sparring. Basically it's partner work where you take turns attacking or defending. One person does a down block, then steps forward and punches. There are 3 "forms" for each belt level. For white belt, the second person will 1) step forward and do a high block, then face punch, 2) step forward into horse riding stance, do a forearm block, and then do two middle punches, or for 3) step forward into horse riding stance, do a knife hand block, and then do two middle punches and one face punch. It's non contact, one movement at a time. They get more complicated as you move up through the belt levels. (Also just for the record, we are learning the Korean terms for all of this, but only a little at a time, and none of those techniques are on our white belt requirements for the terminology)