I’ll offer a second. I really enjoyed Central Park and the Hudson River Greenway during a trip there in 2016. I also really enjoyed riding around on the bike lanes in Manhattan but I was there before most of the delivery guys had e-bikes.
Battery Park offers a nice view of the Statue of Liberty and is also a few blocks away from the Wall Street Bull and the 9/11 Memorial at the World Trade Center which are both worth a visit.
Central Park laps (6 mile closed traffic loop) in Manhattan or Prospect Park laps (4 mile closed traffic loop) in Brooklyn are low stress in the big city. Ride the Hudson River Greenway on the West Side, it runs from Battery Park on the southern tip all the way to the Spuyten Duyvil on the north tip. Lots and lots of bike lanes, but in many areas those are loaded with delivery bikes zooming in and out and too many wrong way riders.