Your first time will be completely awkward. Odds are you will ejaculate in 15-30 seconds. Most young men who are your age ejaculate, and loose their erection before they get put it in.
My first time, I was 14, and it was completely awkward. It was her second time. I ejaculated after about 60 seconds.
You will find out that about 80% of everything you ever heard about sex is not really all that true. Watch videos of the real moon missions, then compare them to science fiction. Note how different it is. Real sex is almost just as different from porn.
The boys at your school that call themselves "pimp" or that brag are still virgins. Sex is not something to brag about.
Real people seldom have sex for more than 5-10 min. A porn movie lasting 15-20 min takes two days to film. Often they put lotion or some other liquid inside her, to make it appear that he ejaculated a lot more than he actually did.
I stared having sex at your age. I grew up poor in a ghetto. Poor people start having sex long before middle class people do. I am now 53, and no longer poor. I have been having sex nearly 40 years. In all that time, I have never once ejaculated on a woman's face, or chest. Sometimes you see alleged "hidden video" of people having sex. If he ejaculates on her face or chest it is likely staged, because few women enjoy that. Most complain if you do not do it inside them.
Most people might look good on video when they are 20-30, but in reality they have much better sex when they are 40, and have had over 20 years of practice.