I have an undergrad in philosophy, but I was kind of a bad student, so take this with a grain of salt.

Philosophy isn't a real subject in the same way mechanical engineering or anthropology are because "philosophy" used to refer to basic everything. Like Aristotle is maybe the most influential European philosopher, and he spent just as much time writing about physics, poetry, and biology as he did ethics or knowledge. Since like the Renaissance, various bits of organized knowledge have become so successful that they split off from philosophy and become their own subjects. Basically, modern philosophy as a subject is a collection of questions that we can't answer very well yet, and also a collection of books that old white professors think are good explorations of those questions.

That said, reading philosophy is cool, and you should totally do it. The main thing you have to do is to pick what sub-group of philosophy you want to study. You can kinda organize these groups by topic or by historical period. Some random ones I think are interesting:

Old-school Marxism: read early Marx, Engels, Hegel*, maybe some old school anarchists like Bakunin, some Mao (on practice and on contradiction). Don't bother with Capital unless you want to learn economics specifically.

Newer Marxism: all of the books people like to talk about on here

Post modern ethics: John Stuart Mill, On the Genealogy of Morality by Nietzsche (warning: extremely edgy), Ethics of Ambiguity by Simone de Beauvoir, general existentialism.

Pseudo-pyschology: Freud, Jung, Lacan*, Zizek

Ancient Greeks: Plato, but don't start with The Republic, maybe try the dialog Meno. Nicomachean Ethics by Aristotle, general books about the pre-Socratics. Diogenes because he's cool.

Buddhism: general stuff about the religion if you're not familiar, like Thic Naht Hanh maybe. Then Nagarjuna*.

*I say read, but picking up some thick philosophy text and trying to work through it on your own is incredibly hard. The ones that I starred especially are basically impossible for a normal human to understand without a lot of background. What you want to do is either find a group where these are read and discussed (which was my introduction as a student), find a really good commentary book, or watch lectures, which is probably what I'd try in your position. There actually a ton of really good recorded philosophy lectures from various colleges on YouTube. If you use yt-dlp you can turn these lectures into mp3s, and then it's basically like listening to a podcast, except the hosts actually know what the fuck they're talking about. Once you get some background, it's worth trying to read the actual text, but again reading someone like Hegel on your own is a similar level of difficulty as running an ultra marathon, except that it won't make you seem cool to anyone.