I'm sorry - I was out of town all weekend and didn't see your response until this morning! Hopefully you did okay! I'm not laughing at the first time camping thing - If you didn't grow up in a family that camped, then it usually takes an invitation from someone who did!
Anyway, for the future, I would recommend salads made with cabbage - they don't wilt, or basically just get better as they do. Do you have Coleslaw in italy? I do variations on that with vinaigrette dressing rather than creamy style dressing. It holds up under any circumstances! You can use either canned/jarred Tuna as a protein, or some cured sausages and hard cheeses. Anything that will hold up to less than wonderful refrigeration is great! How did it go?