I'm just starting out & am wondering what can i do in the way of exercise in my lounge - at night, when the girls are in bed??? I don't have any exercise DVDS, nor any weights... but surely there must be something I can do???

I am assuming you are in a dorm or residence. Would this mean you don't want anything too loud? A yoga dvd might be good in that case. If the stairwells would be ok, you could run up and down the stairs for cardio.
Does your school not have a gym or fitness facility and programs? or are you feeling shy about exercising in front of others. (no judgement from me on that front, I've been there)
good luck, and congrats on starting out.

Squats, lunges, pushups, step ups, dancing, marching in place, situps, crunches, tricep dips, planks, jumping jacks, burpees, mountain climbers, etc.
There are lots of bodyweight exercises you can do. Just google or youtube it.