A repetition is one full movement of an exercise
A set is a group of repetitions.
A circuit is a group of exercises performed back to back with minimal rest.
Perform 1 set of each exercise in the order listed for the correct number of repetitions the first week for one complete circuit. The second week, go through the list of exercises on time and then go through them again for two complete circuits. If your time permits, add a 3rd circuit the third week and after. When you are able to perform the upper limit of repetitions in good form on each exercise, increase the resistance to the next available level and perform the exercises at the lower end of the repetition range. As the exercises get easier add repetitions to the upper range on each movement and when you reach the upper range, increase the resistance again.