I ride on the road, in the mountains, and inside. I would recommend a pair of mountain shoes that are slightly flexible with rubber outsoles. Get a pair with a recessed SPD cleats. These will be good in class as they will work with the bikes there and when you decide to get off the bike and walk around the room to provide encouragement, you will not bust it in front of everyone. Also, once you decide to put new pedals on your mountain bike, you can easily find many to choose from. I have a pair of Shimano and a pair of Sidi. Like them both.
Check out
http://www.roadbikereview.com/
and
http://www.mtbr.com/