hhaha yea that sounds like a bad first experience.
But at least you didnt have your tent leek in a massive down pour and also have your so called mate try and take up your side of the tent/bed.
Ive done all 3 of my duke of edinburghs and each time the guy i was doing it with made sure he was lying at the top end of the hill/slope.
But onto some better info, yes already try out everything you buy first, never trust what the manufacture says. Im 6ft4 and just about fit in a tent thats suppose to be 2.5m (yea its maybe 2.5m on the out side but the innner tents more like 2m)
Always bring a good sleeping bad as you do become very cold at night even if you sleeping bag says its a -ve what ever figure you cant beat a set of thin trousers and tee shirt to keep you toasty and warm.
If your going boozing and you dont wanna leave the tent for a weee, make sure youve got a weee bottle and its got danger tap on it so no one mistakens it for coloured water!!!!
Oh and also make a list of the things your bringing and then look through it a couple of times and think have you forgotten something, or do you really need that extra thing etc