I don't talk much as well (I am originally from Russia, we don't smile much too + I am a software developer). And if I do, I prefer to talk for a reason.

But now I live and work in New Zealand and smalltalks here is a must. And that is really difficult for me.

My advice: just talk. People like to talk random meaningless things. Talk to your colleagues about the weather, about plans for weekends, about their current tasks, ask if they are ok, ask about their car/bike/cat/dog, invite for a coffee etc.

And don't be afraid to repeat yourself. Literally, they ask the same things everyday.