I would check with your local government agencies. They should know of local community gardens. I know there are many throughout the metropolitan area. My work took me to Astoria & Queens for many years before we moved to Tennessee. I met many in your area who also had a love for gardening. Local nurseries could be a good way to seek out a community garden.

Hi, I know this is a bit of a late response but -- there is a community garden in astoria -- in fact there are 2 that I know of.
One is at ARROW community center on 36th street I believe btwn 35th and 36th ave. There is also one called Two Coves which is near the river where 30th ave and Astoria blvd meet at 8th street. I have a plot there and love it!