From the intersection of Wading River Road and South Street, head 0.8 miles west, then turn left onto Dayton Avenue.   Continue about 1 mile, the school will be on your left.  The location is: 151 Dayton Avenue, Manorville, NY 11949

Google:
https://www.google.com/maps/dir//151+Dayton+Ave,+Brookhaven,+NY+11949/@40.8395222,-72.8316561,16z/data=!4m8!4m7!1m0!1m5!1m1!1s0x89e85bc0725dae0d:0x33ac8c5c55724864!2m2!1d-72.8272787!2d40.8395182?hl=en&authuser=0