hello all

i am new to the forums and am hoping to get some answers to all my burning questions
i am an 18 year old female who is 5'9 and 137 pounds. i have lots of muscle mass in my legs but i have skinny arms, a chubby belly, no butt whatsoever, and a bony chest. i look rather odd. what exercises should i do to..
A. build muscle in my arms and chest?
B. reduce the size of my lower belly (i am genetically predetermined to have some fat there but i would be content if i could just reduce it a little)
C. build up some sort of butt?
i currently run at a moderate pace (8 minutes per mile) 7 days a week for at least 25 minutes. i feel lethargic today and i'm just wondering if it would be allright for me to skip a day and just relax? or should i still go out there and pound the pavement?