If you eat breakfast before the ride, you may not need to eat anything on a 2 hour ride. Maybe bring one energy bar if you usually eat one half way. Do bring a couple of bottles of water.

On my club's slower paced rides, most people do not draft unless it is really windy. Spreading out does give you a better view of road conditions. Also, it is easier to see the route, especially if you are not already familiar with it.