Two channels:
A quick way is to have the introduction of the director of the association or above, and generally you can join. See if you can find a connection. If you are looking for a relationship, write two words first, preferably official script (regular script, official script and Wei script are all acceptable), and then show it to your contact if the level is similar.
The second is to apply in accordance with the articles of association of Zhengzhou Calligraphers Association. The condition is that two works are selected for calligraphy exhibition sponsored by the association. I wonder if Zhengzhou Book Association will often organize such activities? I suggest you contact them as soon as possible. If they organize activities, you can get news in time.
If you have one of the above two conditions, they will tell you how to join and join the club.