>them: how was your weekend
>>me: good, how was yours?
>them: good
Give full answers. Instead of "good", go "it was pretty nice, I did/read/saw/watched/went to X, which I found Y. What about you? What'd you do?"
Show interest in them.
A lot of the time people talk about nothing, as in, whatever comes to mind, no specific topic.
Even, if you spend all you time in front of a pc, you probably have things to talk about. For example, articles you've read online, some videos you watched on youtube, depending on the person, maybe games you've played, movies watched, etc.
If you don't have friends you're comfortable with, then imagine your parents/relatives. Imagine walking up to your mother and just chatting about some movie you saw recently. She listens and responds, there's no "omg is he really talking to me about some movie I don't care about", most people are like that.
What requires practice is not being too self conscious and just saying anything.
As for practice, there's also no way around it, aside from actually participating in conversations. So what you'll have to do, is put yourself in social situations. Classic advice is picking up a hobby, where people do it in groups. Could be some kind of class (cooking, dancing, etc.), volounteering, rock climbing, improv, etc.
Don't sweat it, if you can't make conversation immediately, just be nice smile, and give full answers, like mentioned before.
Ask them questions (literally google some "getting to know questions", if you can't think of any, lol).
Interesting quote I've read (paraphrasing):
>You already know everything about yourself, so you should be more interested about finding out everything about others
Though it could be helpful finding out, why you're the way you are. Some self-analysis.
Check out this website, too, I remember there were a lot of useful articles succeedsocially.com