How can I get good at having conversations?

I don’t think I suck in general, but when it comes to having conversations, I’m really terrible. I just can’t think of anything to say or anything to ask about. Maybe it’s because I’m a guy, and guys don’t usually have conversations with each other (preferring instead to grunt or burp, or occasionally beat our chests). But I’m in a job where people expect me to ‘chat’ with them all the time and I just don’t have the foggiest idea what to say. Any advice would be great. Thanks!