Found kitten, need help!

feline leuk test isn't guaranteed to be accurate until actually about 6 months of age - IF the test shows negative. I'll try to get this right as I've recently been through this with some young shelter kittens I fostered.
If you get a positive you can pretty much be sure it's positive, but you can get false negatives which is why the test should be done again at 3-6 months of age especially if you don't know the mother. You could do the test now just to rule out a positive and redo in a few months for better accuracy. If you have any other cats in the house I wouldn't keep a positve kitten, but if this kitten is to be the only cat then I wouldn't worry about it - but be sure to keep the cat inside forever. With good medical care, food diet, the cat can live for sometime. Feline leuk could eventually cause other health problems as it attacks the immune system, like Aids does in people. So often there are illnesses that will results from feline leuk. But if the cat's immune system remains strong enough the cat can live many years.
I'd also offer the kitten a good quality wet kitten food. Gives extra moisture.
They are so cute at that age....

It is the only cat in my house....I have a dog and three ferrets....can ferrets catch feline luek since they are so similar and are pretty much vaccinated as cats?

Also, should I be worried about the "poop situation?" Or am I simply being paranoid? lol  Also, any food recommendations? I just got the Royal Canin babycat since it has such tiny kibbles and he is so small, lol

BabyKat is very good food. Wet food is always good for moisture and meat content.
I've fostered many kittens that age and they can move their bowels w/out intervention. I've never had to help any and so far I've fostered 10 orphaned kittens all around the age of 4 weeks (not at the same time - othewise I'd be totally insane).
He'll probably go when he gets used to a regular feeding schedule and don't be surprised if it's runny. But that's a good opportunity for you to take a fecal to the vet to get meds for parasites - chances are very high he's probably got some in there.
I'm not sure on the ferrets never having had any. That would be a good question for your vet I think. I have no idea if cats and ferrets can share diseases.

We took him to the vet this morning and they were able to get a good fecal sample and it was negative (they gave him some dewormers too, as a preventative).  Thanks so much for your help!!

I took in a stray kitty who was about 9 months old when I got her and she had feline leukemia.  She got really sick about a year later and I had to make the decision to end her suffering.  There are some kitties that can live a very long, healthy life with feline leukemia and others that don't.  If your kitty has it, give her a home as long as she's healthy and that's all that matters.