Here is a list of resources that you may find helpful. 

How to register for tax

To pay tax you'll want a Tax File Number (TFN). You use this when filing tax returns. You can apply for one here.

To register for Deliveroo you'll need a Australian Business Number (ABN). This is the public identifier for your "company". You can apply here. If you registered for a TFN you should enter this in the ABN application form.

How much tax will I need to pay, and when?

You'll need to track the hours you've worked and your expenses to accurately declare tax. You could use a contractor job tracking app Quickbooks.

Click here for a map of listed public toilets across Australia