Google stuff. Like I wind up finding new movies to watch all the time because I'll see an actor in something and end up searching their IMDB page to see if they're who I think they are. Once I'm there, suddenly I'm hearing about all these other things they were in and I end up branching off into 20 tabs with 15 new movies or shows to watch. Take a similar approach with other things you're interested in. Aggregators are a good starting point, even if you're not getting into the comments. All you need is some interest in a topic in your own mind to get the ball rolling. See what questions you have about something and go looking for the answers for it. If you find something interesting, bring it back to us to talk about it and there's your buffer zone. The more activity we have here, like anywhere, the more this site will come to serve that purpose, and it'll do a better job than those other sites because it's designed with positive communication in mind. Personally, I'm still using reddit. I'm just giving up on having in-depth conversations with anyone I disagree with there, because even if you're both polite, somebody's still going to get bombarded with downvotes. If something's that contentious I'd rather talk about it in an environment that's designed to make people nice rather than some ideological arena. It's still perfectly fine for looking at articles.
I also would reccommend googling stuff. You have an area of interest just Google it or something related to it. For stuff like this it's too bad Google removed the "I feel lucky" button (or is it still there but hidden somewhere?). Another great way to fond a starting point is to go to wikipedia and clicking the random article button and just start reading. You'll be surprised at what things you actually might find interesting.