Go. Have fun. Don't worry about what happens or doesn't happen. Maybe you'll end up sleeping in a park and being invited to stay with some college students (Italy), or not have a place to stay and end up randomly in a hostel overlooking a crazy religious festival you didn't know was going to happen (Guatemala), or meet an awesome retired lesbian cop and travel to a village where all the businesses are community owned and the locals have slowly bought out all the large landowners in the area (Ecuador), or accidentally hitchhike up to a volcano because you didn't know you'd missed the last bus and a local wanted to make sure you got where you wanted to go (El Salvador), or you go to a neighboring country on a whim and hear about a hunting eagle festival on the other side of the country and spend a month in an old Russian military van exploring the country en route to and from said festival (Mongolia), or book a flight to a new country and find out your friend's uncle owns a coffee roasting company that buys from a coffee estate and that they'd love to have you spend a month with them learning about how coffee is grown (Tanzania), or maybe there's a cheap relocation rental car available and you can drive to a bunch of national parks and explore the coast without dealing with public transit (Australia), or perhaps your boyfriend's study abroad fling is cool and invites you to stay with him in his flat and take you out with all his friends for a week over your birthday because you happen to be stopping into his country (Spain), or you host some couchsurfers in the US and then visit them when you go to their hometown and stay up all night talking and drinking homebrew (Scotland).

I travel solo all the time, and while I also enjoy traveling with friends, the reality is that most people can't leave on a trip in June and return home in December like I can. Thus: go and have fun. Bring a book or 10 for when you have alone time (and there will be plenty), and cards for when you meet people (there will be plenty of that too).