Al this varies from state to state.
Basically, is the sports ground Private Property or Public Property. If its Private, you need owners permission to take photos. If its Public, ask the local council if there are any restrictiion to take photos. If its Public Property, but the club is leasing the land, you will need to ask the club permission to take photos.
If you are standing on the footpath taking photos into the sports ground, they cant really ask you to stop.
You also need to lookup the State laws, oterwise they might lock you up & add you to the Child Sex Offenders list.
What has happened locally here (eg the Junior Netball) most clubs have passed rules that permision has to be gained from the club to take photos. So parent taking photos of their own kids will be asked to stop unless they have been given permission.