Perfectly normal, natural and absolutely okay to masturbate at any age. There are absolutely NO harmful health effects.
I started masturbating when I was around your age, possibly younger.
Masturbation has NO negative effects on a persons physical health, psychology or physiology.
It is perfectly normal and healthy to enjoy masturbation. Dont feel guilty for doing it.
I don't know of any negative effects. I've known of a mother masturbating her year old son for the same reason my 15 yo girlfriend did it to me when I was 19. She loved to see me orgasm and watch my facial expressions and involuntary body motions. She told me it made her feel powerful doing something to me that I couldn't control. I guess she was right, she owned me for about 2 years.
How did you learn how to do it? I learned from a cousin when I was 10.
Nothing to worry about. Perfectly safe and very normal thing to explore and enjoy those pleasurable sensations. Don't let anyone make you believe you are bad or slutty or that you are lacking morals for masturbating. Nothing to do with stupid religion too. Just do it, enjoy yourself and do it as often or as little as you want. It is your body and your sexuality and you are comitting no crime pleasuring yourself. It will NOT harm or hurt you.