At 13 I was allowed to wear blush, lip gloss and mascara. By the time I was 16 I could then wear foundation and eye shadows. So I think at 13 a little bit of makeup is fine. Mom always told me less is more so I never did wear too much and I still don't.
I didn't even experiment with it until I was 21 and realized that I had an opportunity to intern at a youth delinquency center. I figured I better figure out how to do my face so I could look my age so they wouldn't mistake me for being a delinquent when I went for the interview lol
I started wearing make up in 9th grade. I would put powder on and mascara. But I didn't start wearing eyeshadow until senior year. And even then it was just a tiny amount on special occasions. I was in college before I started wearing eyeshadow everyday. And I've only gotten good for my standards since sophomore year (learning how to blend well and tiny tricks to really accentuate features without looking like a clown) Now I wear eye make up, lip colors, blush, and highlight sometimes. I just got my own foundation though because of a really bad experience with foundation that led to many many breakouts D: but this one is much better :D
I used to wear make up only on special occasions. Even then, I very hardly did it on my own. However, if I have to say when I actually started putting make up on more regularly and by myself and actually bought my own make up, I was 26 when I started.
The first time I put make up on I was 14, it was for my first dance performance, but on a daily basis when I was 19 lol so this year ahaha I dont wear much tho just eyeliner and mascara and not everyday