Congratulations!
Searching for who we are, where do we come from and where we go is a basic human need just after food, reproduction and social interaction. It is completely right to be interested in such a things. It is also possible to find the truth, I can certainly tell that, but that would be for long, as always.

My parents translates, writes, publishes and sells books. My father in particular wrote a book by himself, published it, and now he's renowned among his inland colleagues. Astrologers, specifically. The point is, that when there is some wise, true, original and very useful stuff in the book, as it certainly is in the example, you can expect to be approved by an interested public group of customers. I'm looking forward to when the book will be published in USA.
However, a philosophy has a long tradition, and there is diffcult to find anything new, so it would be nice to post a few of excerpts to demonstrate what is new on your book. I hope the book is big enough, so there will be enough to read even if you publish it's excerpts. Feel free to show us, local experts, some your texts to impress us

Today's technology is more advanced as always, and made the book publishing more friendly to low-amount printing. These new electronic printers can be easily and quickly accustomed to print a several hundreds of books, and then re-accustomed to someone else's books. It's cheap, fast, and also easy to order a reprints, so you don't have to keep a big stock. In the old times, only a thousands of books would pay off for the work with setting the printer.
In case you don't know, the publishing company takes care of an advertisement of the book, so it's possible to find the book in book stores in all the state. But it is also very recommendable to advertise and sell your book personally on the internet or on your lectures if you perform any. (well, my parents does a lot of lectures and sells a books from their editions there)
When your book is sold by book stores, you won't get much money, unless it's selling well, to a lot of people. This is why a personal selling gives the most money, unless it's a bestseller with some interesting name, like "A Theory of Sex In Zero Gravity" (or whatever the crowd likes) But of course, if you live in a big country and write in english language, then there's much more of potential customers and a selling situation may be different.

In order to be a good writer you have to write alot. So think of it this way: you may be young, you may not be taken seriously, there may even be good reasons why older, smarter people won't take you seriously; reasons that you, in your youthful confidence can't see or understand yourself. BUT! The sooner you start writing, the better you'll get at it.

There are two options: either you have wisdom and insight well beyond your years, in which case your age will be a positive boon in terms of getting noticed. What publisher wouldn't want to publish the first book of a philosophical prodigy? Or alternatively, you'll write an overexcited, slightly youthfully naive little thing that few will take seriously, and that you yourself will sit and read back with a smile on your face in ten years thinking: "Oh how young and full of passionate idealism I was back then".

But if the latter is the case, don't despair, for it will mean that you started writing at 17, thus ensuring that that 27 year old, reading back his first writings will be a more accomplished, wise and insightful writer, because he started early. And it will not mean that your thoughts and ideas are wrong now, it just means that they will get better, and more thought out as time passes.

Just do what Natural wrote, and write for your own sake, and don't worry about the end result. Get cracking, and not a moment too soon either. I started writing little dabbles of this and that when I was 14 (I write fiction), and today I may laugh at my earliest attempts at storytelling, but I'm still glad I had the moxy to go for it. I'm a better writer today because of it.

And also, in order to be a good writer you have to read alot, and the older you are, the more time you have had to read. If you keep reading philosophy, appologetics, and also just whatever takes your fancy, it will help you with inspiration, some because you agree, and some because you disagree, and it will make you a better speller, and strenghen your vocabulary. I'm from Denmark, so English is not my first language, and if it can be said that I have a reasonable spelling, grammar, and vocabulary in English, it is all thanks to the many books I've read in English.

So don't take this the wrong way: I think it's brilliant that you have confidence in your own opinions and writing abilities, and you should focus that ambition and confidence and just get cracking. But don't be too disheartened if you don't get all the attention you deserve at first. For every page you write, you are becoming a more accomplished writer, and you will get the recognition you deserve in due time.

I, for one, would be glad to read your book, if you finish it. So that gives you one more reason to write it, allthough you only need the one reason that you want to do it for yourself.

Keep up the moxy! Ambition is a good thing!