It’s one of my fav summer things to do and completely free. The Brooklyn bridge park has a kayaking kiosk, operated by volunteers throughout summer. You can do alone or with a friend. The volunteers and guides are super helpful and friendly. There are no changing stations around the place so need to figure out your own. The views are absolutely exceptional. I would recommend going around sundown to have even better views. You can book on website but the tickets go pretty fast. They do take walk-ins all the time but might have to wait about 15-25 mins depending on the day. Kid friendly too!