Advice on who should quarantine and who should isolate, how to prepare and how to support someone who is sick during a quarantine period can be found here https://www.dhhs.vic.gov.au/self-quarantine-coronavirus-covid-19 or by calling the COVID-19 Hotline 1800 675 398.
Your local Council is also a great support network. Be sure to contact them and ask for the Coordinator of the Public and Environmental Health Department. https://www.viccouncils.asn.au/find-your-council/council-contacts-list