The only issue here on LI tends to be the courts with lights, which are few and far between.
During the day time there are courts at every high school in addition to public parks, so it's not hard to find a free one, especially since no one plays tennis anymore.
My favorite place to play is a local high school that just had all of its courts resurfaced (they used to be awful) almost no one knows about this so there are 9 courts and no one is ever there during the summer.
I only bring my ball machine out early in the morning to avoid bothering people on adjacent courts.
3.5 player. Equipment: Prince NXG OS, hybrid kevlar mains/poly crosses 50 lbs