If your business turnover is greater than $75000, you have to register GST and lodge BAS quarterly. There is optional GST if your turnover is less than $75000. And you can choose whether to lodge quarterly or yearly if you register GST.
Generally sole traders use their name as their business name (trading name), but they can register a business name under their ABN as well.
Sole traders are taxed with an individual income rate, currently they have a tax threshold $18200, in practice it can be up to $20500.