It's a lot easier than you think. The first time I hit the road I was pretty nervous about what I was going to do but everytime I've arrived somewhere new since I've just been excited to be somewhere different; new friends to be made, another culture to adapt to, new things to be seen and done...it's just so fucking exciting! Everytime you go somewhere new it becomes easier to adapt. I suppose I've learnt quite a lot about travelling over the last through years by trial and error. If you want some advice keep reading, if not stop hear or you'll get very bored with what I'm about to write.
If you're really interested in travelling, the very first thing you should do is sit down and of all work out where you want to go and roughly how long you want to go for, make sure you have enough money to pay for the flight and survive at least a couple of months without any income. Don't rely on getting paid work as soon as you arrive somewhere knew, sometimes it can be harder than you think. Then it's a good idea to go and buy a guide book or two and work out a very rough plan...what are the things you really want to see on this trip and where are the places you really want to go. Don't bother planning a precise intinerary because I guarentee it will change once you start travelling. Arriving somewhere knew without anywhere to stay can be surprisingly daunting, especially at the start of a trip so try and book a hostel in advance for the first few days of your trip(
www.hostelworld.com is a good site but there are loads like it) and make sure you have the address on you when you fly (not in your baggage as your bags might get delayed or lost) so you know exactly where to tell the taxi driver to take you when you arrive in the new city. After that just take everyday as it comes. It's important to realise that you'll have shitty days every now and again and there will be times when you want to go home. Make sure you have at least two cash/credit cards and NEVER keep them together (that way if you get mugged you still have access to cash) and be prepared to be ripped off from time to time (especially in less developed countries), it will happen, and when it does just accept it and get on with it. It's very possible that some stuff will get stolen from you. I'd say about 1/4 of the travellers I've met have had something stolen from them...try not to let it ruin your trip, a camera/phone/ipod is replaceable. And also, if you're an american in an anti-american country (like many south american countries) I recommend telling people that you are canadian if they ask you where you're from.
If you go with friends be absolutely certain that you could be with them 24/7 without getting pissed off (imagine if you had to share a prison cell with them. If that thought fills you with dread then you're going with the wrong friend). Once you start getting annoyed with someone you're travelling with they won't stop pissing you off until you've gone your seperate ways. And make sure you BOTH have enough money to do what you want to do...there's nothing worse than both of you having to go home because one of you has run out of money.
Whenever you go somewhere new make sure you know about the customs and culture of its people. One of the best tips I can give is to try to learn a few words of the language before you go...even yes, no, please and hello are better than nothing; you'll be amazed at how much better treatment you get from the natives if you make an effort. The internet is very useful for vocabulary.
Especially when backpacking (as opposed to actually settling down somewhere for a while which is what I'm doing now) you get pretty used to meeting new people and just having an open mind. I know it sounds cheesy but you really do just live everyday as it comes; situations can change in a matter of minutes. You might meet a couple of people in a bar and decide they're good fun and before you know it you've already agreed to travel together for the next few weeks. If they turn out to be dicks then no problem, just split and carry on on your own until you meet some more people. Don't be afraid to talk to new people, especially in a hostel where everyone else will be in the same boat as you.
The only time in my adult life that I've been totally worry free has been when I've been travelling, and it's a good feeling. The only thing I ever worry about is money but it's usually not a problem, there are always jobs going for travellers. I got short of cash in Peru and ended up working as a barman in a nightclub in Cusco for 2 months. It was crazy, I was working and drinking 6 days a week from 9pm until 8am but they were 2 of the best months of my life and I was earning money at the same time which allowed me to travel for another 2 months instead of heading home.
I could probably go on forever writing advice about travelling and living abroad (maybe I should write a book!) but I'm gonna stop here. Any questions send me a message. If anyone's thinking of travelling in South America then drop me a line, I might be able to recommend some places to you.
Travelling becomes normal very quickly. One of my favourite things is when I get home and look through my photos after a few weeks. You forget all the bad times and realise that you have just had the most incredible amount of fun and some awesome experiences.
Don't be afraid about travelling...get out there and do it or you'll only regret it once it's too late.
Woah, this has become a LONG post. Sorry.