Start with the basics. Socrates, Plato, and Aristotle form the foundation of Western Philosophy.
Note that philosophy requires a significant amount of thought on your own part. There are parts of these three (and many others that follow) that are absurd. See Aristotle on many scientific matters. They lived in a society with slaves, so you’ll find some hierarchical views of humans that we now reject.
What’s most important from there is what you care about.
Is it epistemology — the study of knowledge? Or ethics — what is right, wrong, just? Is it political philosophy, be it democracy or monarchy or anarchy? Are you curious about power? Want to explore consciousness, what it is to be a “self” and the repercussions of those answers? Maybe linguistics, how we communicate, use language, and the strengths/weaknesses of it.
There is philosophy of sport, of war, of aesthetics; on gender and race; on the meaning (or not!) of things; on life and death and god(s) and spirituality; on machines, computers, and artificial intelligence.
I believe that the Greeks are important because they are so foundational to what comes after. Everything, the saying goes, is a footnote to them.
But after that, follow your questions. You can spend a hell of a lot of time reading things you don’t deeply care about. It will be a slog and without an external forcing function, you’ll probably lose interest and give up. For me that is philosophy of language, specifically a fair bit of what I consider to be nonsense in the past sixty years.
A good way to find who to read is to first know what people call it (e.g. epistemology) and then either find college courses or online lists. Go back to the early work and work your way through the Core. From there you’ll know enough of what the questions are that you can branch out.