A few things to keep in mind about eating and drinking when you are sick:
Drink more than you usually do. Keep a strong focus on getting lots of fluids, even if you don't feel thirsty.
Drink water or juice. Sports drinks are OK, and many people like the fact that they replace electrolytes. But, for the most part, people with fevers or colds don't run a risk of major electrolyte imbalance unless they are vomiting or have severe diarrhea.