There are tons of LI shows, both big and small. Check online at
Antique Classic Collectable Cars - Special Interest Vehicles Online car weekly with classifieds, activities, and club listings. and I have a calendar on my site of shows that I go to
DF Concours - Car shows
The best cruise night for me is Oyster Bay on Tuesdays, IMO the best cruise night anywhere. 5:00-9:30 Audrey Ave, Oyster Bay.
Next big show is at Belmont Racetrack
The Original Long Island Cars