WILL I NEED A VISA IF COMING FROM OVERSEAS?
Yes, depending on which passport you hold, you will need either:
1. VISITOR VISA SUBCLASS 6OO:
https://immi.homeaffairs.gov.au/visas/getting-a-visa/visa-listing/visitor-600
2. ELECTRONIC TRAVEL AUTHORITY SUBCLASS 601:
https://immi.homeaffairs.gov.au/visas/getting-a-visa/visa-listing/electronic-travel-authority-601
More information on the pricing of visas, how to apply, and processing is attached in the links above depending on which visa you require
CAN I TRAVEL ACROSS AUSTRALIA WITH MY VISITOR VISA?
Your visitor visa, whether it's a 600 or 601, or any other visa, permits you to travel within Australia. For further information, please consult the terms outlined in your Visa Grant Notice.
I WISH TO VISIT THE GROOM'S FAMILY IN SYDNEY, HOW CAN I PLAN MY TRIP?
All the events / ceremonies will be taking place in the Queensland (QLD) State, in Brisbane (capital city of QLD). And those wishing to visit the groom's family in New South Wales (NSW) State, in Sydney (capital city of NSW), can book a multi-destination trip.
For example someone from Europe ( let's say Paris - France), would book a Paris to Brisbane trip and then a Sydney to Paris trip.
Once those trips are booked, the person would have to book an interstate ticket from Brisbane to Sydney.
Google flights (https://www.google.com/travel/flights) does propose interesting deals. Just remember to use a private (InPrivate / Incognito mode) browser.
ACCOMODATION
We recommend that individuals join together and arrange accommodations as a group. This approach will streamline the process and reduce costs.