Hi Tessa,
If you are convicted, then you will have your licence suspended for a minimum of 6 months. The court may impose a longer suspension period and worst case, there is a possible custodial sentence associated with the offence. However the court does take into account your previous driving history when deciding on the penalty.
The list of penalties for DUI in Queensland is here:
Being charged with drink driving | Transport and motoring | Queensland Government
Because there is a possible custodial sentence associated with your offence, you should seek legal advice before going to court. You can start by getting in contact with Legal Aid Queensland. You can call them on 1300 65 11 88, Monday to Friday, 8.30-5pm.
At the bottom of Queensland's Legal Aid page for Drink Driving Offences, there is a list of other legal advice and other related services that you can get in touch with, such as the Queensland Traffic Offenders Program:
Drink driving offences