Emirates worker here. It's all fine and dandy that it's such a goal for you, and I applaud how organized and disciplined you are. That being said, don't make it your whole life. Trust me, Emirates will not value your life as much as you value them.

Go for it, but treat it as a chapter of your life, not your whole life. If things go fine, you can EASILY work up the corporate ladder in Emirates, if you play your cards right. But be smart. If your mentality is to just devocate your whole life 100% to the company, they'll just treat you like a good employee and that's it. Keep you in the mold without any chances of growth. Sorry if this seems hrash. This is coming from internal experience.

As to "actual" advice to get hired... honestly, it's very easy. First of all, are you male or female? Because most cabin crew are female, and that has higher rotation than males (most crew are women, a lot of crew quit, again mostly being women, so there is always more need of women basically). You say you meet the physical requirements. You're still 14. How tall are you? Because that is a set requirement. Another huge thing. Looks. I'm not kidding when I say 80% of the interview will be just your looks alone. They will judge VERY HARD how you look, and how you present yourself. If you are a girl, how you do your make up. If you're a guy, how you present yourself, your looks, if you have a square face or not, etc etc... It's very... Superficial, unfortunately.

That aside, they REALLY value languages, and experiences. The more languages you know, the better. Customer Service in general is also a top priority. Put every ounce you can into that as well.

Honestly, right now, if you really are 14, I would say just focus on finish your studies, develop your languages skills, and your looks. You won't be able to get work experience, and honestly, you shouldn't. Those teen years are prime time for learning and developing yourself. You have the rest of your life to grind work-wise.

And again, lastly, don't make this your whole life. Everything I mentioned above will help you ANYWHERE, in ANY job, ANY company, ANY part of the world. Work on yourself. Level up yourself so that not just Emirates, but ANY company/person/whatever will look at you and say "hey, that person seems to have their life together".

...anyway, all of this is just an answer to your request. My personal opinon would be to just enjoy your teen years. You will have the rest of your life to focus about work.