I def recommend against starting with das kapital, at least until the advanced / intermediate stages. Its a slog, and not really the best introduction.

Here's a Marxism study plan, with a good number of audiobooks / audiobook torrents for them.

You can absolutely do that, but it may be extremely difficult.

I would personally recommend starting with The Principles of Communism and then following it up with How Marxism Works. Then, you can dive into Wage Labor and Capital and Value, Price, and Profit.

With the easy overviews of Marxism as a whole, and the Marxist critique of Capitalism out of the way, I would go to Socialism: Utopian and Scientific for philosophy, and Critique of the Gotha Programme for Marx's vision of what Socialism may look like. Read the Communist Manifesto now, where you have the background knowledge to fully understand the text and appreciate its fire.

Optionally, add Lenin here. Imperialism: The Highest Stage of Capitalism explains how Capitalism has grown since Marx, using ideas laid out by Marx but not fully observable until Lenin. I would say this is actually the most important work for understanding Modern Capitalism, but since it builds on Marx, it's important to read this one after Marx. The State and Revolution is Lenin's other major work, and it goes over the strategy used during the Russian Revolution. Important for historical context, even if you disagree with Lenin here.

All of this combined is, I believe, shorter than 1 full volume of Capital.

Hope that helps!