Clicking the picture above will take you to the official website for Green lakes State park with all sorts of information. I invite you to go to that page and click on the "Virtual Tour" link to see a 360 pic of the beachfront area including the building which houses the community room. 

Clicking the picture above will take you to a nice map of the park. Where it says "Bathhouse" in the upper right corner is where the building with the community room is.