Socialism

I wouldn't say the Communist Manifesto is the most basic entry point. It was written in a different time for an audience who would have understood a lot more of the references than we do today. It also applies dialectical and historical materialism without really addressing what that means, which can create a bit of a sticking point.

I didn't fully understand it until I'd read a lot of other Marxist texts. The first time I read it (when I wasn't a Marxist), I just thought it was a bit shit. The second time I read it (when I was becoming a Marxist), I thought that it ignored the crucial information that I was looking for. It was during the third read-through (after becoming a Marxist) that I got the most out of it.

These readings were years apart, btw. And my earlier issues with it were down to having certain expectations of what I would find. I'm only saying this so that you don't lose heart – texts that should be easy to read or which seem easy to some people aren't always easy to others.

Now, I'm with Soviet Snake and I do recommend it as an early text. But it's a starting point, to get a flavour of Marxism. If you don't/didn't get on with it, there are other texts.

Engels is a better writer than Marx. He usually gets to the point a little quicker. Not to say I dislike Marx's style; but Engels is more direct. Give his sole-authored works a try.

In light of your OP question, I suggest Socialism: Utopian and Scientific: https://www.marxists.org/archive/marx/works/1880/soc-utop/index.htm.