I'll have to agree with Rokket. It's who you know, not what you know.
I'm not sure what they're called in the US, but a semi-decent "entry route" to the entertainment industry (esp touring) is being a "loader"- basically a shit-kicker who helps load/unload truck, rig/focus lights and hang PA. Whilst it sounds like crappy work (which it is), the majority of loaders wouldn't have it any other way. Plus, there's always need for more loaders, and the job interview consists of "So, you've got two legs and two arms? Welcome aboard!"
Whilst not a career in any sense, it will give you the skills, and, more importantly, the contacts that you will need to try and tour.
Unfortunatley, getting into the audio side of touring is a bit harder than trying to geting into the lighting or mechanist side, however it is possible. Befriend the systems engineers (if they 've got time to talk, that is). Whilst most bands will tour their own personal FOH/Monitor engineer, the Systems guy will generally be sent by the company providing the PA system. Get to know the systems that go out in your area- I4, V-Dosc, Mylo, Vertec etc. If you show that you know the stuff, then chances are someone will notice, and when it's time to get new staff, your name will pop up.
Admitedely, this is a fairly slow process. If you choose to go the traineeship/cadetship route, chances are it will be 2-3 years before you're considered "mature" enough to even go out on gigs.
If you're a "sideways entry" (ie, hired as a skilled engineer) to a company, then chances are you'll still be running systems for a few months before they even consider putting you in front of a console. (Once again, if you know someone, then this time can be drastically reduced...).
As with any career, it takes time, however, unlike a management or buisness job, the path isn't always clear. There are times you'll wake up from nightmares that you'll still be living off rice for the rest of your life, but, most of the time, you'll have a blast.
Touring can be a great experience, espically if you're young (so long as you're over the legal age, obviously). "Living the dream" is always interesting, and, although you'll be doing back-to-back 18 hour days for a fortnight, you'll always feel great after those first few post-show beers.