I started shaving at sixteen, but there were lads shaving younger than that in my school. Some people just end up with odd facial hair growing patterns, so an early shave is pretty much required, not only for social purposes (super important, like!), but for tactile ones. I remember when I was sixteen, I found my new found life buddies to be uncomfortable, and I'd be picking at them all day. Actually, I still do that.
I should've started shaving earlier, because a mark on my face (from chicken pox I think) makes some hairs grow far quicker than others. As a result, I end up with a collection of annoyingly long streaks, and in high school, people found them rather amusing. Fortunately, I did too, but that's not the point. I just started shaving at sixteen because I got a shaver for my sixteenth birthday. If it feels like a good time for you, go ahead and get stuck in, and feel the relief when you wash it all afterwards. That's my favourite part of the shave.
Maybe I should wash more often.