Leagues
There are numerous leagues available to clubs to field teams in. All clubs are involved in at least one league, whilst some are involved in multiple leagues.
Each league operates independently of each other and they make their own decisions, particularly on which clubs are involved and how much it costs to enter. They also cater for either junior or senior players, but not both.
One way of deciding what club to be involved in may be to pick the league first and then pick the club.