Do NOT give it milk.
If it won't take dry food, then give it wet food to start, until it's old enough to eat dry food. Wet food is nasty in the long term.
Purina makes fine food. Buy kitten formula. Stay away from seafood (also nasty). A relatively mild chicken formula will suffice.
PLENTY of fresh, clean water, changed often.
Do NOT put food and water near the litter box. If you're gonna keep everything in the same area, at least separate them a bit.
Scoopable, unscented litter in the box. Scoop daily. Place kitten in box oftern until it gets the hint. Then you can let it roam once it figures that shit out.
Small fuzzy toys, corks, jingly balls, whatever.
Don't subject kittens to sudden moves, harsh noises. Soothing voice, calm demeanor, deliberate movements.
Something soft to curl up in. Old blanket. Even a towel.
If you keep it, I have more tips. Good luck with the little fucker. Cats can be a real blessing around the house. They can also be a pain in the ass. Most of that fault lies with the owner.