Hello, calligraphy is obviously not illegal, and the country encourages everyone to learn calligraphy.
If you want to open a small training institution, it is recommended that you go through some industrial and commercial procedures.
I guess you are also a calligraphy lover, right? It is actually very important to choose a good writing brush when writing calligraphy. You can find this article and read "China's Top 10 Calligraphy Brush Brands (With How to Selection and Maintenance of Calligraphy Brushes)", which introduces some good writing brushes and how to How to select and maintain a brush, along with pictures of how to develop a new brush and the correct way to hold the brush. I hope it will be helpful to you~