I can't offer much more advice than what's been offered. I will say that if you're going abroad and it's possible, rent a cell phone. I've had a cell phone (or a portable wi-fi device) every time I've gone abroad in the past few years and it's been absolutely invaluable. I've been able to meet up with friends, use the internet to figure out where I should be going or what train I need to take. And knowing that I have it in case something does happen has added a great peace of mind. It was so nerve-wracking travelling alone at first, but getting over the initial feelings of judgment ("Oh god, everyone's gonna know I'm alone!") and worrying I wouldn't have as much fun if I wasn't with others, I found that it was actually way more enjoyable. I met so many more people by myself, and got to do everything at my own pace. Do your research, know the language, trust your instincts. That's really all you need for a successful trip.