Hi, climber,
Others have posted link to materials on getting your license. My wife and I are hams. The test questions and answers are all online, and you can take free practice tests online to test yourself. You may, if you wish, download all the questions and correct answers and just memorize them. (So much for skill. :->) Being 14 doesn't matter. There are _tons_ of people younger than you that are hams.
As for talking around the world, there are two issues. If you get your Technician's license (the entry level), you will not be able to talk around the world on your own radio (there are internet links for it, but that's another story). For worldwide communications on ham radio, you need a General license, and you need more expensive radios and expensive antennas (expensive is relative - search at HRO for HF radios, then search for antennas).
As a Technician, you are limited to UHF/VHF frequencies, which will not give you much more than "line of sight" communications without repeaters (a more powerful radio that repeats your transmissions and which uses a better antenna). The good news is that emergency responders (including hams) almost all use UHF/VHF radios for communications - emergencies are local. You can get new handheld radios for under $200, and used radios are under a hundred.
Go to the ARRL site someone else mentioned at
http://www.arrl.org/arrlvec/examsearch.phtmlwhich is the page to search for exams in your area. I also suggest visiting
http://www.arrl.org/FandES/field/club/clubsearch.phtmland finding clubs in your area.
Most people in clubs are very helpful, and there may be some people who have more radios than they are using; you might be able to buy one inexpensively from someone who can show you how to use it. You might also borrow one and see how you like it before you buy.
I have a page of links at
http://www.civex.com/ham.html(the section for clubs is in my area; use the ARRL page to find them in your area). The page gives links to new and used sellers, online exam materials, reviews, and some more.
Good luck and have fun.