A) search the business name on ABN lookup and see if you can find the legal entity name (ie. Company name, trust name). Once you know this, search the ASIC website for "published insolvency notices".
This published notice will indicate who the liquidator is.
B) contact the liquidator and ask about options to purchase erhe business. Their job is to liquidate the assets of the business, so if they can sell the business for money, they generally will.
C) you'd really just be buying the business, so that fact the previous owner went into liquidation, isn't really your issue. However it can have flow on effects which may impact your ability to operate that business.
For example, supplies burnt by the liquidation may simply refuse to deal with that business (even with new owners), so if it's a business heavily reliant on a particular supplier/s then it'd be a concern.
Other than that, it's normal things like reputation damage to the brand of the business and so on.