Ah, the old Shaolin Kempo yellow belt test, circa 1984. I don't think you would have been asked to test if your instructor didn't think you were ready. Practice your blocks, punches, and kicks. Maintain good stances and balance. For your martial arts journey, learn to use your hands as well as, if not better than your feet. One punch is not enough. Practicing single punches are a waste of time. Get in a fighting stance, not a horse stance, and punch the bag rapidly alternating hands until you can punch for a minute if you have to nonstop. Don't worry about power at first but rather flowing and speed. Your goal is to overwhelm your attacker with an unending flow of strikes. Kicking high is pretty, but not smart on the street. Practice hard, devasting, and low front, back, side, and roundhouse kicks to a wavemaster bag. Learn Ju Jutsu techniques to control your opponent when you don't want to strike.
In the movie "The Perfect Weapon," Kenpo is described as "a combination of ancient fighting techniques and modern scientific principles. An unending flow of motion, a force that can overwhelm any attacker. Every move creates a specific reaction in your opponent, each reaction leads you to your next move. Every strike is a block, every block is a strike. Each move flows into the next. This logical and sequential flow of motion is the essence of Kenpo. Kenpo can be the most lethal of the martial arts. To control the power of Kenpo, you must first learn to control yourself. Train your spirit as you train your body - developing inner strength, balance, and harmony as you learn. A master of Kenpo is more than an expert in the martial arts, he is a master of himself."