Amtrak's Adirondack only operates from New York's Penn Station to Montreal's Central Station. If you are referring to Quebec City, then you will need to connect to VIA Rail Canada at Montreal.

As for the service on the Adirondack it's a basic daytime train with coach seating and a cafe/lounge food service car. The food is going to be of the pre-packed and microwaveable variety.

The nicest part of this ride is the scenery.
Between NYC and Albany the Hudson River will be on your left. North of Albany Lake Champlain will be on your right between Westport, NY and the border crossing at Rouses Point, NY. The scenery in upstate New York is breathtaking, it's too bad they don't add dome cars at Albany like they used too years ago.