As best I know there are no reservations. First come first serve. But hopefully all nice and can share. If you want to use the large roofed area for a large group then you will need to make a reservation and pay well in advance, as these are usually reserved by many groups way in advance. Note that at that time there is a fee charged to enter the Croton Point Park.
I would call asap just to make sure. I know that in some Riverfront parks there is a fee for the use of the grills.
Yes you can
No it's first come first serve reservations are only made for the cabins as far as I'm concerned
First come first served
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