There isn't really a good way to learn sex. Sex ed in school covers the "Tab A, Slot B" basics and hopefully some of the safety measures, but you're lucky if they admit oral sex exists, let alone get into the intricacies of foreplay and kinks and social nuances. Parents, unless you grew up in of those weird "we're just very open" families, probably were even less help. So where do you learn these things?
Peers? Maybe it's because I hung out with a seriously nerdy crowd, but in middle and even high school my peers didn't know much more than I did and they spread ridiculous misinformation about sex. This is why "can you get pregnant from giving a blowjob" is always in my Google search terms.
Porn? Porn doesn't depict sex. Mainstream porn tells you nothing about foreplay, nothing about how to get someone in bed if just showing up wasn't sufficient, nothing about how sex is positioned or how it will go, and absolutely nothing about what women or men actually enjoy.
Reading? Eh, some. I read a bunch of sex advice books and websites before I had sex, and I guess I learned some things, but it was hard to sort out the misinformation there as well, and a lot of it was about the controversial and difficult aspects of sex, not the basics that they assumed everyone already knew. I could read "how to give an excellent blowjob," but I couldn't read what exactly a blowjob was supposed to be like in the first place. It took me some time to understand that you don't just stick it in your mouth and suck.
In the end, it's 99% on-the-job education. Which, as on the job, is a euphemism for "learning by screwing up." Everything I know about sex, I learned by making some poor guy go "ow!" or "what the heck?" or "uh, honey, that's not doing it for me." And the guys in turn didn't really know what they were doing. I bumbled around for about five years before becoming remotely competent at sex. And I'm not talking fancy moves here, I'm talking stuff like how to move my hips and how to tell if a guy is close to orgasm.
The weirdest part is, because sex "education" is so private and haphazard, it never really gets standardized. I've run into a lot of people who thought they were bizarre because of something that was very common, or who had bizarre practices they thought were standard. If your education is all from women's magazines and personal experience, it's easy to come to believe you're the only woman on earth who comes in less than twenty minutes. Or, conversely, that every guy comes in thirty seconds and that's totally normal when you're young.
Some of this is the joy of discovery, and most of it gets sorted out by age thirty at the latest, but I do wish there was a "Sex for Virgins" book that went through all the basics of "after he gets all panty and his dick gets sorta extra hard and purpley, about a tablespoon of white stuff will come out in several diminishing squirts" and so on. It would have been fantastically useful.