If you really want to start from zero, you have to start with the greeks. You can skip between the greeks and marx.
History of Philosophy from Copplestone is good. It has like 11 volumes lol, but the first one is the most important.
You can also listen to History Of Philosophy without any gaps. It's really good.
After that, IMO reading some secondary lit on hegel is key.
Then read Marx. If you're not too interested in the economic stuff, you can skip vol 2 and 3 of Capital. There's a lot to read.
At this point you should be radicalized. It is honestly hard not to see things as Marx and Hegel saw them.