Aang feels the power within, but to make it work on him, he should practice every day. Step on the column and defend youself building the obstacles and jump when you have blocked the attack!
Aang wants to pass the ancient test that will probably wake up his power. He will learn how to control it, but the test itself is quite complicated and dangerous. Step on the column and avoid various things that will try to throw you off the column. Build the obstacles and block these attacks to jump on the other column when you are ready!