If you are a sole trader, you must lodge a tax return on the normal tax form for individuals.
Tax will be payable on the profit (income minus expenses) you have made from your sole trader activities, together with any other income earned, such as wages and salary income, interest, dividends, ect.
Sole traders are treated no differently for tax purposes than individual salary and income earners. However, if you make a profit from your sole trading activities, the Australian Taxation Office (ATO) will ask you to pay an estimate of the tax you will be liable for in the following year, on a quarterly basis. This will be done on what is called an Installment Activity Summary.
Sole traders can learn more. Visit the page which explains how it works and follow the steps to lodge your tax online now.
Tax File Numbers And Tax For New Australian Sole Traders
Watch this video for an explanation on how to ATO can help individuals set up a Tax File Number and begin to trade under a Sole Trader arrangement.