Well, I had the same problem back in London when I was there for nine months. I couldn't find any people outside of the language school. I tried social networks but these attempts failed as sites of this kind require you to pay for functions like "signup to this event"...probably not all of them, but there were some. It took me few months of loneliness until I found a group playing Dungeons and Dragons every week.
I was hoping to attain enough speaking skill to get myself a decent job here in Prague, in my home city.
And I did. Decent, but ironically, a czech only job. Colleagues communicate in Czech only and noone wants me to speak english at all. So after those 9 months in London, I've been getting frustrated for having no real usage for it.
I'm 23 year old programmer, I know computers and stuff, don't expect me to enjoy getting drunk or going for a wild night in any of the Prague's nightclubs.
There are these particular Czech style teahouses in Prague, which I have not seen anywhere else - these are nice places for getting along. As well as is a nice walk in Stromovka, Petřín or in the countryside just outside of Prague. You don't need to worry about obtaining the tickets as I remember myself getting totally confused of the London Ticketing System hell (Czechs have THAT simpler at least).
I'm not looking for a girlfriend. I'm not going to promise that we'll really get along but I know for sure that I'd write myself a response if I knew back in London that there was a forum like this. Let me know if you are struggling as I was