If you will be cycling on the road get a road bike. Sporty road bikes won't be great for carrying your junk to school, junk hauling roadbikes won't be great for training competitively. But if I were you I would get a race oriented bike, and haul my junk in a backpack. I have no knowledge of your local market, so IDK what you can get for $400, but if your buying used, stay away from singlespeeds and anything so old it has downtube shifters.