So. I have never gone to cons ALONE per-say, but they were usually my older sibling who I didn't want to hang out with and they didn't want to hang out with me. After you make what I call "con friends" it makes going to a specific con easier because, you have people there sometimes before or after you get there. I guess it isn't really good advice for your first con alone but, it's good advice for future cons alone, right?
Usually, at cons there are random, not on the list games, I know on occasionevery con, I run a game of werewolves and meet and make new friends. You are WAY more than welcome to join that.