It's useless to write that you are a student union, but you can use your position to accumulate some experience of accumulating basic common sense and collecting some experience of less useful business resources. If you can use your position to develop yourself, it is good to open campus activities.
Many times we will regret what we wanted to do but didn't do. Only a few times we will regret what we did ... so join in if you want to exercise. You may regret it for four years after joining, and you may regret it for a lifetime if you don't join.
Just make good use of it Seeing how you make good use of any meaningful activities is good for your exercise. On the positive side, a school is like a small society, and it is beneficial to enter the society in its infancy.
Joining the student union is a freshman, and a new leader will be chosen when you are a sophomore. Looks like you can go up. If the junior is still an official, he will generally quit. You can expand your communication scope and improve your personal ability.
I hope my answer is helpful to you.