Think of it this way.
You may not be qualified or have experience as a hairdresser, but you can purchase a pair of scissors and you can operate them. Over time you may learn the tricks of the trade, and you may even become good at cutting hair.
But along the way you’ll probably suffer through some very sad haircuts and you may end up at a salon paying exorbitant prices for a fix-up. Occasionally it might take months (or years) to recover from a botched haircut.
Bookkeeping is the same. There are many things you need to know and a range of experience you need to have in order to be a good bookkeeper. You also need to keep up to date with changes in payroll, tax, GST, PAYG and other ATO legislation.