How does anyone get ahold of someone to reserve a pavilion as I have left numerous voice message's and got no response?

First come first serve till memorial day.

Not sure you can reserve a pavilion

What "last ride" said.

Try Holyoke City Hall

You may want to wait a couple weeks and call back. I believe (not 100%) that they have regular hours starting around memorial day weekend and there will be someone there for reservations more often.