Hi, Emily,
Here is a good link on introducing a new cat:
http://messybeast.com/first-impressions.htm
Your kitten will pretty much decide how much food she needs. I wouldn’t feed her dry food soaked as it tends to grow bacteria. A good quality wet kitten food is best. My cats (both girls) get one raw meat meal a day (needs to be high-quality, either human-grade from a supermarket or a high-quality pet food raw meat from a reputable company) and one wet food meal. Good raw foods are chicken necks, chicken livers, ox heart, lamb or beef kidneys, minced steak, minced veal, etc. You can feed her some dry kitten food but don’t wet it.
She is very tiny and really too young to be away from her mother. Try to kitten-proof your place, get down to her level and try to look at your house/apartment from ‘her’ level. Cords she could chew, things she could climb and fall from, things she could get stuck under,drawers and closets she could get accidentally shut in, toxic house plants she could chew on (google them), things with water or liquid in (an open toilet) she could fall in and not be able to get out again. Be particularly careful with washers and dryers as kittens LOVE piles of (dirty or clean) laundry, never leave the doors open and always check before you turn one on that kitten is not inside. I tend to put little kittens on my pillow as (hopefully) while it’s warm and close to me, it’s not likely I’ll accidentally squash them, but you could also make a little nest for her in a box, with an unwashed sweater of yours in it, to smell of you, and a stuffed toy to comfort her. For more info, check the other threads, I seem to have been posting a lot of advice on looking after little kittens tonight!