Good advice. The ProleWiki reading list is a good place to start. I also got a lot out of Rev Left Radio and Proles of the Roundtable podcasts. They have some great theory episodes a well as themed/topic episodes on art, Cuba, and more. They're good for reading recommendations, too.

Also worth remembering that it's not necessary to read every page of every book. For some books, yes. But not all of them. Sometimes it's enough to read the intro and/or conclusion. Sometimes just a select chapter. It depends on what you need/want from the text. Even with Capital I started by reading a chapter here, a chapter there. It wasn't until a year or so later that I sat and read it cover to cover.

One difficulty with reading new material – and most of Marxism is new material to most people because western education has severe shortcomings – is that every sentence can be a string of unfamiliar vocab. Each word might represent a new concept, covered by a whole body of literature. If all this is new, it's sooo dense. But the more you learn about and around a topic, the more the concepts become familiar and the easier the texts become to read.

That's why I advocate starting with management texts/selections, and building up. It's also why I think podcasts are helpful. It's all about helping to build up a core knowledge of the basic concepts. David Harvey's books are good for this. Especially Rebel Cities. It's short and applies Marxist concepts to everyday examples (wine production, coca cola, student housing, access to public spaces, etc) without using too much jargon.

Plus, if communists had to read everything before they could call themselves a communist, there wouldn't be any!