Half way through
Thinking since it was my first time using the software, I was afraid I couldn't catch up. However, it turned out easier than I thought but still more practice on it.
So first, to start, we have to create the file/ image in Photoshop and separate the moving objects into different layers. After imported into the AE (After Effect), we arranged them accordingly and parent them. Then only we start setting the timing of the animation.
The outcome of the exercise: