need help for my kitty!!!

[muddno]

i just found a kitten two days ago. her mom killed by lorry (and the rest of her siblings... poor family...) so i'm taking care of her. this is my first time taking care of a cat. i think she's just 2-3 weeks old. i spoon-fed her milk (nestle omega). now, the thing is i dont know how much should i give her. and to make things worst, my friend 'accidentally' step on her (god knows how much he hate my cat, always purring in the night). now, i cant afford to take her to a vet (how much that will cost me?) but i dnt want to lose that cutie... any suggestions? need help really2 bad...