Advice about working out?

I weight 133 lbs and I've been this weight for as long as I can remember. I cant gain weight for the life of me , no matter how much I eat or try.

I'm skinny but I have meat on me, like my stomach, love handles etc. I also have perky, full c cup boobs

I've always wanted to work out but have always afraid because I don't wanna lose my boobs

I know when you work out, you lose fat and that includes your boobs right ?

Is there any way to tone up or grow my lower half without working out the area around my boobs?

And please don't be rude or judgmental.. I've always been hella insecure about being skinny. I don't have curves or a big butt and I always thought my boobs were the only feminine part of my body so that's why I've been weary about working out