Only shave your legs if and when you feel like you need to.
I started shaving my legs at 12, but that's because I have medium-brown leg hair, and I hit puberty kind of early.
My mum, however, doesn't need to shave her legs at all. She has very blonde, very fine hair, and you can't see or feel any leg hair. She used to shave her legs just because everyone else did when she was younger, but stopped because it didn't make any difference, so it seemed pointless.
If you're like that, you might never have to shave your legs either... which is awesome!
Trust me, shaving/waxing is not a chore you want!