You will need a visa to come to Australia. One type of visa you can apply for is an E Visitors Visa. It is suitable in a number of situations, including if you are going to Australia on holiday, on business, or to visit friends or relatives. It is valid for 12 months, but you can only stay in Australia for three months at a time.
To qualify for an E Visitors Visa you must hold a passport from an eligible country. It is an online application process, and you must be outside Australia both when you make the application and receive a decision. You may need to show you have enough money to cover your time in Australia, but that doesn’t happen in every case.