I am also looking to race a tractor for the first time this year, the age thing you mentioned, and live in the Saratoga area. The only track in this area that races tractors is Capital District Lawn Mower Racing Organization their track is in Esperance at the Rt20 and Rt30 intersection behind the Hillside Traven. There are other kart tracks in the area that sometimes host tractors i.e.: Dodgecity in Howe cavern, Caroga Creek kart track, Turkey trot Glens Falls, there's one more I can't think of at the moment.
I repair small engines for a living and as such have built a small lawn tractor bone yard that I sell from and am always looking to buy more. If you would like to get together and help each other out let me know. I am still undecided as to what class tractor to build.