New kitten...I have a couple questions?

I got my first cat ever a couple days ago, she was 6 weeks old exactly the day I got her. Anyways, she just seems to attack evereything lately, when I try to pet her sometimes she just attacks my hand biting like crazy, and when my little brother kinda crawls around after her or just tries to pick her up or sometimes when anyone tries to pick her up she arches her back and her tail hangs down and I don't want her to grow up into a mean, scared, biting or like never comes when called and just avoids us kind of cat. Is there any way I can avoid this?