Hey youngByron,
When I first started reading this site in November of last year, I became hardcore into working on just fundamentals...and not talking to women. It wasn't until March that I started approaching women regularly, and when I did, my fundamentals (specifically vocal, body, and social) fell like a boulder off a cliff. Unfortunately, there is no substitute for approaching women. It's like any skill you learn. If you watch videos on how to play guitar for 5 months, you're still not going to play like Jimi Hendrix when you pickup a real guitar for the first time. You're going to find all of the mistakes and problems that you couldn't find by running scenarios in your head.
That being said, being 16 and living in a religiously-zealous country can make it difficult to talk to a bunch of new girls regularly. But I dare you to challenge yourself and find women by being creative and finding ways around the problem. Because that is when you will be truly successful with women. And that's how you get your "vibe" down. Bad boys get what they want, but it's only because they bend the rules and find solutions to problems that are difficult to pinpoint.
Anyways, good to hear you are working on fashion and body fundamentals, posture is definitely a hard one at first. Malls are especially good places to find young girls your age. If I were you, I would travel to the nearest place with a larger population to approach girls at least once a week or every other week. That way, if there is absolutely no other solution you can come up with, you can get a diagnostic of where you are and what you can improve on until the next week or two. Lastly, age means nothing. Age won't stop you from achieving success with women. Only a lack of trying to find a solution.
Good luck,
Jake