If you’re given a sentence of actual imprisonment, then your sentence starts immediately. You’re taken from the courtroom and into a police watchhouse where you are usually held for a few days. Once transport to a prison is organised, you’ll then be taken out to the prison for processing.
Generally, men are sent to Brisbane Correctional Centre (BCC) and women are sent to the Brisbane Women’s Correctional Centre (BWCC). Following your admission, you may be transferred to another prison depending on space, the length of your sentence and your classification.
Caxton Legal have a great guide about prison life which can be found here.