As a freelancer, I only use Harvest and excel. I only need a bookkeeper for catching up with record keeping for the end of year return. I do not need GST, or BAS or any company things, mine is sole trader. You must know Australian taxation basically.
My invoices are all in Harvest (export to CSV) and my expenses are all over the place in various bank statements, which are in PDFs.
So you have to go through the statements and copy over the ones that are legit business expenses; also note down the 'Drawings' I call Jens Wages. I have made a small start in Excel, attached. Then it is a matter of checking if I accounted for all income as well.
Please be kind with your rate.