If you plan to come to town prior to our wedding, Jennifer's family owns a breakfast and lunch place in Nyack, NY. You SHOULD call ahead to get your name on the list, as it will probably be busy with a wait for a table.
If you're interested in going for a walk/hike along the Hudson River, you can visit Hook Mountain.
The town of Nyack has a variety of shops and restaurants that you can walk around to shop/eat. The town itself is one block up from the Hudson River. Feel free to walk around and enjoy the small town. You can also walk to Memorial Park which is right on the water, with a view of the Tappen Zee Bridge.