After your graduation, you have several options available to you whether you stay in Australia or head home. You may be able to continue your studies in Australia to pursue a higher-level qualification or another field of study, you may be eligible to undertake post study work to put your newly gained knowledge to use and gain work experience in Australia, or you may choose to go home to undertake further study or work there.
If you decide you want to undertake further study or work in Australia you will need to check whether your visa allows this or whether you need to apply for a new visa. You can go to the Department of Home Affairs website to check your visa conditions and find out what your options are.
Wherever your path leads, think about joining an alumni group from your institution. It will help you stay in touch with your classmates and can provide you with great benefits and opportunities.