Dear xx:
In order to further enrich our cultural and sports life, promote the development of badminton in our school and provide a platform for badminton lovers to communicate, learn and improve, the school trade union and the school badminton association have decided:
It is planned to hold a ball gathering activity in xxxxxx this week, and hold lectures on badminton knowledge, technology and injury prevention. The specific activity time is set at XXXXXX. Enthusiasts, including beginners, are welcome to actively participate in the discussion and hope to attend on time.
School trade union, school badminton association
X year x month x day
I hope you can adopt my answer.