Hi Chook,
Everyone is different. Only you'll be able to tell. Are you masturbating? You should get a really good feeling. It may feel like you have to urinate the first few times but don't stop - keep going!
There's only one way to tell. Masturbate and see if anything comes out when you orgasm.
Everyone grows at their own pace. I'm 13 and only started making semen a few months ago. Some of my friends already look like full-grown men.
Not sure how "in detail" i can get here, without getting punished.
So send me a private message, and we can talk about it some more if you like.
Can you cum with out having sex
Yes indeed. This is one of the great things about masturbation. You can learn about how your body functions, and experience orgasm and ejaculation, without actually having sex