When I was in highschool, I dated a girl who had a ferret. I don’t know if the ferret was old or drugged, but it was cool and calm all the time. I don’t know how, but they domesticated the shit out of that thing, so it ended up being like she owned a giant hamster or really skinny cat. She did have to clean it a lot though to keep it from stinking.
Congrats! Since you’ve already done some reading I’m sure you know what to expect in terms of nip-training, smells, vacinesand such… if not the links will be helpful 
Like someone already said, avoid instant rice. I’m not sure about all grain products, but I was never in the habit of feeding mine anything with grain in it. They love sugar, but too much can mess with their digestive system. Some things like apple baby-food, chicken, eggs I think, and lamb is good. I found this linkthat might help, this linkmight also help for quick easy bites.
Honestly, they love using corners as their personal bathroom. Your best bet is to keep an eye on which is the one they use most, and start cleaning the others. They have little litter boxes designed for ferrets you can install into his or her favorite corner and watch him or her like an eagle. Any time it begins to look like he or she is about to have an accident, transport him to the litter box, give him a treat for each time he goes in the box. No where else, Ferrets are incredibly intelligent, they’ll catch on.
Cleaning helper: Nature’s miracle.
I’m not sure how well these work but it might be worth a try: Corner Deterrant Springs
They will always have their war dance. They will always have seemingly endless amounts of energy. They do calm down a little after a bit of time and age, and eventually they’ll learn your down times and come perch on your shoulder while you surf SRK, or dook and dance when you play Super, or whatever your game of choice is. She’s still very young, they’re all crazy when young lol.
I hope I helped 
should mention that ferrets require a fatty diet, so any food that is fatty is generally good. Like it’s been stated, they ARE carnivores, so meat is where its at.
I just give em cans of purina cat food sometimes, or any meaty type treat
“For many years, the common recommendation was to feed premium dry cat or kitten food, but that recommendation is now considered out-of-date. As the science of ferret nutrition improves, there is little doubt that premium ferret diets are the best to feed ferrets. Still, if you are unable to find a good quality ferret food (consider ordering online if nothing else) you may have to settle for cat food. If so, make sure it is a premium diet (e.g. Eukanuba, Innova). Use a kitten food, high in protein, but as your ferret gets a bit older (4 years or so), switch to an adult food. Again, you must check labels, and pick foods with only high quality animal proteins at the top of the ingredient list, and make sure they are high in fat and very low in grains, sugar, and fiber. Avoid generic or “grocery store” brands at all costs, as these are typically very poor for ferrets.”