I have a questions: Every time I wear pants or jeans I feel like scratching the pubic hair all the time. I am just 13. Is it normal for me to masturbate?
As you develop into a man, your body grows more terminal hairs. Terminal hairs are the darker, stiffer hairs, like the ones on the top of your head. While they are flexible, they are not nearly as flexible as the vellus hairs on your body. Vellus hairs are the small, nearly clear hairs that cover most of your skin. One of the purposes of vellus hairs is to give you feedback when something is touching your skin. As you change, many of your vellus hairs change into terminal hairs. That is what you are seeing in your pubic region. The problem is that the new terminal hairs, being short, give too much feedback and it makes you feel itchy. As the hairs get longer, this calms down, but the transition stage is annoying.
One solution, if it is particularly annoying, is to wear underwear that has a close weave so that your hairs don't get caught by the fabric as much.
Masturbation is the instinctive result of your seminal vesicles getting full. The impulse is to relieve yourself by ejaculating semen, which then allows more semen to be produced. When a boy starts masturbating really depends on when his body is mature enough to start producing semen. There is no set age, but it will start in either stage 2 or stage 4 of development.
The problem that too often arises now that you are masturbating is that there is an impulse to pursue the pleasure, even when you don't need to ejaculate. A lot of guys get caught up in pornography because they want something sexually exciting to see in order to allow themselves to masturbate more often than they need to. However, pornography is a sin (I Thessalonians 4:3-5), and it tends to lead to other sexual sins. Enjoy the feelings of relieving yourself, but don't chase after the pleasure because it will lead you into sin.