Sorry to piss on your bonfire mate, but this is a lot harder to do than you think.
The council will not let you use the land with pallets and stuff, as they are not fixed, and are considered unsafe. If the council help you, it will only be for a park made of concrete, etc. and will also have lots of rules, and will probably become boring as you improve.
A better idea would be to find someone who owns land, other than the council, and ask them, as they are not obligated by as many rules and regulations. They may offer you their land to use, on the condition that it is kept tidy and you all sign disclaimers that you will not sue if you injure yourselves, etc.
Well done for trying though, and I hope you are successful in finsing someone and sorting out comps and stuff.