I was the youngest child and got a lot more freedom than my brother and sister. I used to wander, doing my own thing under the radar, but I didn't get in bad, bad trouble.
Think about the photo before and after, never during. The secret is to take your time. You mustn't go too fast. The subject must forget about you. Then, however, you must be very quick.
Map out your future - but do it in pencil. The road ahead is as long as you make it. Make it worth the trip.