Hey bro I had the same experience when I traveled back in Oct 2017 to Europe. I went completely solo and I'm going again in 2 weeks! We're gonna barely miss each other because I was planning on going to Berlin too! Anyways your best bet is to socialize with other travelers in hostels. Hang around in the lobbies, two of the hostels I was at they had free beer and little events so people could get to know others. Nobody gave a shit that I stuttered and people were cool and genuinely interested in hearing about my experiences. (I was military, now law enforcement) so people asked me questions about the US Army and what not. ​ I had a blast hanging out with some British dudes in Amsterdam, and a Canadian chick while I was in Ireland. (I even made out with her, couldn't get lucky so to speak but maybe this time I might!), and a US Marine while I was in Paris. The Marine and I just started talking because we both recognized each other as military because of our haircuts and there's a brotherhood between all service members, so we just hung out, got wasted, and never saw each other again lol. All of these people I met at hostels, and most except for the chick, I met by just offering them a cigarette. I don't smoke regularly but I brought a pack just for socializing. I only smoke when I drink and that's rarely ever. So bring a pack of cigarettes and just have it out when you're outside if you see other people smoking. If someone asks for one, strike up a conversation. That's my tip, just don't get addicted lol.