If so who do I contact to reserve a space and a time on a particular date

Last year I set up all.my stuff by the grill and area I wanted and the people that worked at the park told me I had to leave cause it was reserved . If your going to do something there reserve your spot. I wasn't the only one who got booted . Lots of other families too.

you need a permit for 20+ people, go to the Parks Website for more information and to put in an application

If so what

That's not necessary . Just get to your desired location early .

No one Whenever your ready Just go

You asked half a question