This is your sign: if you're on the fence about studying abroad, do it!
First and foremost...
Think about the classes you want to take as well as the destination. When you start planning to study abroad it's really easy to think of where you want to go and what you want to get out of it. For me, I wanted to go to Paris first. It just so happened that the American Business School was there, but I realized later that I needed to be more fluent in French than I was. London was my next choice, and I found a great business school that had classes I really enjoyed. Had I gone to London and attended a mediocre school I would have been wasting my time and not enjoyed my stay as much. I got a lot out of my classes and the city itself, so thinking of the type of program you'd like to enroll in is huge!
Make a few notecards about current events, prominent figures, etc. where you will study abroad. I've always been one to keep up with the news - I thank my parents for making us read the newspaper and watch the Nightly News for that - but there were so many people I studied abroad with who couldn't even name the British Prime Minister (in case you're wondering, it's David Cameron)! During my semester in London Margaret Thatcher died, and while I generally knew who she was, I had no idea why the country was so torn on the topic of her funeral. Had I bothered to do even a bit of background research on her I would have felt much more comfortable talking with British friends about it and wouldn't have felt completely clueless. While I kept up to date on the basic current information, I should have also thought of major events of the past too. TL;DR: do your research!
Google Maps the walk to and from your tube/subway station or school. I can't tell you how many times I did this before I went to London, and it helped so much when I first got there. Not only did I have a better understanding of where I was, but it got me so pumped to go! When you finally get to your host country you will thank your past self. Your mom, who is worried sick about you, will too!
Make a checklist of things you want to do while you're overseas. I made a checklist of 100 things I wanted to do, and while I didn't get some of them done, a lot of my plans were already half-way organized by the time I got around to doing them. Try printing off your list on a cute card and hang it up in your room, that way your goals will always be front and center!
Have two copies of every paper you need. This includes driver's license, passport, passport photo, birth certificate, acceptance letter to your study abroad organization, acceptance letter to your university, flight tickets, directions from the airport to your flat/dorm, and anything else official you can think of. Trust me, better safe than sorry.
If you have one, bring your nice camera. And use it. Looking back at my photos, I realize how lucky I was to live in London, which is such a beautiful city. My problem is that even though I brought my DSLR, I never used it, so all of my photos are from my iPhone! I always thought my DSLR was too big to want to take all around London since I didn't have a bag bigger than a crossbody. I can't believe how shortsighted I was, especially since my camera was hardly big at all! I love my photos that I have, but I wish I had utilized a great thing that I had already brought all the way with me!
One tip for while you're abroad...
Don't be afraid to just explore. On your own. One thing I'm so thankful for is that I learned how to have fun on my own in London. I didn't have the ability to travel outside of the UK as much as I would have liked, or as much as my other friends, so I spent more than a few afternoons and mornings choosing an area of London and then exploring. I had so much fun seeing how lost I could get before having to turn back, and I found some great hole in the wall places I would never have experienced. I wouldn't replace that time for the world!