First of all, a child is not suitable to learn anything before he is four years old, because before he is four years old, some of his bodies are not well developed and are not flexible at all. So after four years old, you can see what he is interested in and then let him learn. Then after the age of four, it is basically the age to go to kindergarten. When you go to kindergarten, you can observe what your child is interested in, and then you can let him learn.
But if you want him to learn calligraphy, then in daily life, you must influence him to get some calligraphy things from time to time and let him accept those things slowly. In the future, he will be interested in these things. At this time, you can let him learn calligraphy at this stage.
Then be sure to be with him when practicing calligraphy, and then buy some templates for him to write with. I think children should let him start with hard pen calligraphy, because soft pen is difficult to control and it is very easy to stain him. So you can buy some basic copybooks and let him learn slowly. At least after the strokes are slowly understood, give him a more advanced copybook and let him write with copybooks word by word.
Later, when there was more time, he spent more time writing and practicing calligraphy, and calligraphy naturally improved. He can also write a good hand at school. The influence behind him is also very profound. Therefore, it is necessary for children to start calligraphy at an early age and practice it slowly. Of course, as long as they spend a long time and work hard, calligraphy will naturally look good.