There is more than one way to help a local sports club. Alongside coaching and match-day jobs, organisations advertise for people who can assist with events, administration and communications.
GoVolunteer maintains listings for sporting organisations in Victoria, with a separate search for Melbourne. The available roles change, so it is worth checking the actual commitment before putting your hand up. A single event can suit someone who cannot take on a weekly position.
If you are organising volunteers, make the request specific. Say what the job involves, when help is needed and who the volunteer can contact. A clear two-hour task is easier to consider than an open-ended request to help run the club.
For a role that interests you, ask the organisation about training, supervision and any checks it requires before you start.