Do I have to reserve a pavilion for this weekend if I was to have a party there?

Yes you do.

Yes

The answer is yes i forget the # but call them and they will assign you a spot for a few hrs and its posted on the pole that day whos party it is and from what time til what time ... its a bit pricey

Don't know for sure if they take reservations, call the town offices and check

I would say yes