Good impulse to read theory, but 150y/o theory is not where I’d advice people to start. At least the german originals of what you recomend there are fairly hard to read. Plus they lack the development of marxist theory that happened since then. For example Gramscis thoughts are so freakin important for marxism to be applicable to this society being far more diverse than good’ol working class in the factory vs. Monopoly man capitalists. I’m sure there is updated marxism and introductions available in english. (Dunno, Harvey maybe? Mayo?)

Also “how to conduct yourself as a leftist” sound strict af and kinda deterministic.

The ideology defines who is on what side of the “vs.”

“The Idea of the Yeti was long called bullshit, but now I got myself bigger shoes”