Cars moving while the public is in is the main safety risk: lock vehicle movement once the public gate opens.
Letting any seller sell food: unregistered food stalls are your problem as organiser (Auckland Council).
Leaving rubbish and unsold goods behind loses you the site next time; make sellers take everything home.
Assuming school or church land needs nothing: a regular market on private land may need resource consent (Auckland Council).
On council land an event permit is needed (Auckland community event $104-215) and a regular public market needs a market licence; a regular market on private land may need resource consent (Auckland). Outside food stalls must be registered.
* General fundraising information, not legal, tax or financial advice. Money figures are examples and estimates, not promises. Check current official requirements before you commit. About this guide