First, you need to be aware that generally because an area is open to the public for use does not mean that it's open for commercial use - and what you're aiming to do is commercial use. Operating a business in most 'public' spaces such as reserves, marine parks etc is subject to some form of licence or permit requirement.
As for what these are, what they're called, where to find them and what legislation they're under - that's a potentially very long list that would take some research to do (i.e. I'm not going to answer it, and I doubt you'll find someone here who will).
Your first step is to figure out exactly what areas you want to use. Next, determine who controls the land: i.e. local council, state government or federal government. Then, start searching on the internet along to lines of 'licence' 'permit' and the area you want to use. A bit of clicking around should at least get you the name of the relevant authority to make enquiries with. Go from there. Be prepared for (a) cost, (b) conditions, (c) being told no (but that doesn't necessarily mean an absolute no), and (d) having to prove yourself. Public spaces are meant for the public to enjoy, and preserves are meant to be preserved - any business use is going to be restricted in some way to keep the areas as natural and accessible for all as possible.