Viveksena is the Army of Swami Vivekananda. Members dedicate themselves to serve others seeing God in them. There is no place for your ego. You are just an instrument of God.
There is a reason it is called a Sena – an Army. Every soldier in an army must show up, has to be committed and must be disciplined in carrying out the mission. In a regular army, the superior officer sets the mission and enforces the discipline. Here you volunteer for the mission and disciple yourself to carryout the mission. Parents and others assist you in this process, but you are responsible for your own actions.
You are under no pressure to volunteer for any activity. Consistent with your other activities, volunteer only for the activities you can participate in without difficulty. But once you commit to an activity, you must show up and have the discipline to perform without any one prompting you or calling you.