It is estimated that it is impossible to practice a good hand in five days. Even if you can practice "shape", you can't practice "strength" of words. You see, people have been practicing calligraphy for decades, and they write when they have time. If they can practice for five days, why do they practice for so long?

Zhonggongge is to make the font arrangement look better when you write Chinese characters. You can search some hard-pen calligraphy tutorials online. I suggest watching Pang Zhonghua's and practicing every day, starting with the simplest strokes.

I hope you can succeed.