Is this the residential part of your award or expedition stage?
1) Food should have been discussed in your preparation stages. I bought a fair few packets of super noodles and 'all day breakfast' and camping food. Check out Go Outdoors, they have a good selection. Don't forget your emergency rations, Marzipan is on of the best in my opinion.
2) It was a long time ago that I last participated, back then the rules where that males and females would sleep separate. I'm guessing that is still the case, but again, your expedition leaders will tell you. They have guidelines to follow and sleeping arrangements is one of them.
3) I think you'll find that peeing outside is inevitable. Some of your campsites (if not all of them) will have on site facilities, but for wild-camps, it is you and the great outdoors. Just don't pee on anyone's tents or shoes, and keep it out of the view of public. As for the old "number two", same applies.
4) Yes, toilet paper is a must if you want to maintain any sort of personal hygiene. You can buy travel toilet paper.
On the subject of toilet paper, wet wipes and baby-wipes are useful for a clean in the morning. You most likely won't have a shower for the duration. The best advice is to be careful what you take, because you will be carrying it the whole time. Pack essentials and not tin cans like one of my colleagues did.
Hope you enjoy yourself!