I would recommend SEP (https://plato.stanford.edu/) for your exact purpose. Although not entirely structured as a guide on philosophy, it is very much akin to Wikipedia in that you can get lost for hours. I highly recommend stretching out on the patio with your laptop and a cigarette and make like Camus for an afternoon. As a philosophy major, it is an invaluable resource.

I'd say reading having a read of Bertrand Russell's 'A history of Western Philosophy' is a solid start. [0]

You can branch out from there, based on who appeals to you personally.

[0] https://www.amazon.com/History-Western-Philosophy-Bertrand-R...

I've been working my way through the podcast "A history of philosophy without any gaps". I find the episodes are a perfect length for my commute, and the presenter seems to be pretty well informed:

https://historyofphilosophy.net/

One of my personal project ideas (that I'll probably never get around to) is something along these lines.

I want to create a way for people to follow a particular idea throughout time. So imagine picking a topic, like free will, and you'll be able to use a map and timeline to trace writings on that topic throughout history. Each piece of writing would be linked to the sources it was inspired from, as well as the pieces of writing that it inspired.

while people are listing some good philosophy resources, it's not quite the same as CS course on the original link.

But it could totally be done for philosophy, there are some great lectures online covering enough that would be equivalent to a degree. It wouldn't be that hard to extend such a site to allow people to find small groups of people for philosophical discussions either.