Traveling isn't all sunshine and rainbows, especially for those on a budget that can't just swipe a credit card when things don't go as planned. I'v been backpacking for 6 years now, from 2 week trips to 4 month trips, with all sorts of budgets in between. I am no expert, but these are a few things I have learned from my mistakes that will help you prepare for your first trip.
When I first started backpacking, I would constantly over pack. In what world will I ever need 7 dresses and 5 pairs of shoes that I don't even wear at home? In reality, you are backpacking, not dining out at some bougie restaurant. It's normal to wear the same outfit for days at a time and it is okay to not wear make up, you are traveling. If you are moving between countries or cities, you will be walking A LOT. No one wants to lug a massive suitcase down flights of stairs to the metro or across cobble-stone streets. I can tell you from experience, it is not fun.
Pack Carry-On Friendly Luggage
Along with packing light, make sure you pack light enough to be able to fit it as a carry on. If you decide to take a flight with a local budget airline, you can avoid the high fees they will charge for checked luggage and the potential of the airline loosing your bag.
This is one of the most important things for any level of backpacker. It is rare that everything in your trip goes as planned. You might stay up late partying one night and miss your flight. The more you travel, the more you will realize, the rest of the world doesn't cater towards their people in certain ways like the west. Some countries, the buses may decide they don't want to run that day, or they're going to be four hours late. Punctuality is not everyone's forte. But instead of getting upset, go in with an open mind that things may not go as planned.
Be Open with your Plans
Going along with being flexible for when things don't work out, be willingly open to new ideas. You may have a list of things you want to do on your trip, but be open to change. You will meet so many people that will give you another long list of things to do that you may have never heard of. Hostels will often list popular excursions and events for the week that you can attend. You also may fall in love with a city and want to extend your stay, or the opposite, maybe you got all that you could out of a city in one day and are ready for something new.
Trust the Locals
Obviously, I am not saying follow that strange man down a dark alley at night, but do not fear the locals. Depending where you go, many people are fascinated with the western world and they want to get to know people from it. Countries like Cuba and Vietnam don't necessarily have access to the internet in the way that westerners do, so they are extra interested in learning your culture.
Don't be Afraid to go Alone
"I was never going to go if I waited for someone to come with me." This is one of my favorite quotes because of how relatable it is. I wanted someone to travel with so bad and realized that wasn't going to happen. Not everyone shares your passion and it's okay to branch out and find those who do. The world is not as scary as the media makes it out to be. The reality of traveling alone is...you are rarely alone. There are so many solo travelers world-wide and they flock together. You will have people to go to the clubs, hike, or scuba dive with, whatever your interest is, there will be someone else traveling that wants to do it too.
Say "Yes" More
Backpacking will push you to try things you would not ordinarily do at home. Try the strange looking street food and say "yes" to things you'd be too nervous to do anywhere else. This is your time to be care free and open minded. Create those hilarious stories you can share with your friends and family back home. And if you don't like something, you don't have to do it twice.
Perfect your Negotiating Skills
Taxis are sometimes the biggest tourist trap you will face. They will see you are a westerner and automatically charge more than they would a local. Negotiate your price before getting in the taxi to lessen the amount they will rip you off. Have an idea of how much you should be paying, so you can prevent spending 5 times more than you should be. Don't be afraid to tell a taxi driver "no" and try the next one.
Carry Some Cash
Credit card machines are becoming more popular world-wide, but there are still some countries that do not utilize them everywhere. Many taxis and public transport will only accept cash. It is helpful to get some from the airport ATM's before leaving to have it just in case.
Learn the Language
You don't need to become fluent in 5 different languages before backpacking Europe or Asia. But it is smart to learn a few key words that will help you get by. English is very widely spoken, but you may find yourself in a smaller town or a country where it is not.