Wearing a bikini for the first time?

Well im 15, and i havent actually worn a bikini showing of my stomach. I mean i wear one but i usually wear shorts and a tank top over it. but im deciding to wear it without. And i knowi need to shave my legs, arms, armpits, and bikini line. But i dont know if i should shave my lower back and stomach. I am a burnett so my body hair is dark. there isnt much but you can still see it. should i shave or just keep it. my mom is out of town so i cant get a waxing kit. thanks(: