More people should read Marx. Even if you don't take everything he says, much of what he writes can be directly applied to today and can help people make sense of their current situations.
Capital is Marxism, plainly, but I'm obviously not going to recommend that to start. Instead, if you want to be more well-read than 90% of people, read Wage Labor and Capital as well as Value, Price, and Profit. You can find these on the Marxist Internet Archive for free: http://marxists.org/
No problem! There are a ton of useful works, the Manifesto of the Communist Party is fun and Principles of Communism is a good FAQ too, but VPP and WLaC make up the best 1-2 punch of Marxism you can get.
Kinda agree, as Marx's critique of Liberalism/Capitalism is top-notch. However, the texts are so hard to read and it feels like you need an university degree to even be able to finish or grasp some of them.