Well I mostly talk with people who are already pretty disillusioned with the world around us, and I offer them an alternative way to think in terms of class struggle and building worker power to get everyone's needs met. I might use a lot of general arguments about how capitalism requires unemployment to maintain its reserve army of labor, or point out how the system needs to waste a lot of commodities over time to maintain prices at a high level, that sort of thing. But in terms of hard facts I usually just point out to the political and economic situation we live in (small island colony of the US) and give them a way to think about it that makes a lot more sense than "well they create jobs so it's good that Americans are building all their factories in our tax haven, actually".

Of course if you can back it up with more facts and online sources that's a bonus but it can backfire, IDK if this is too anti-intellectual to say but I've always found that if you're talking with laymen it can be more of a hindrance than anything else because for each source you may find that indicates that capitalism is obsolete, there's a billion Cato Institute, Heritage Foundation, or some other billionaire/NED funded outlet that says the opposite and it looks just as convincing. So I find it easier to rely on lived experiences. Which is why it never works to talk with people that have had life handed to them with a silver spoon, because those people will always be inclined to conclude that this system works and poverty is just a result of poor choices on the part of the individual.