I'm new to philosophy and I want to know which books or topics I should start with.
Some good introductory books on philosophy are "An Introduction to Philosophical Thinking" by James Rachels, "Philosophy: A Very Short Introduction" by Peter Adamson, and "The Stanford Encyclopedia of Philosophy: The Big Ideas" edited by Edward N. Zalta. You may also want to consider reading some classic philosophical works such as Plato's "Republic", Aristotle's "Nicomachean Ethics", Kant's "Critique of Pure Reason", Hegel's "The Phenomenology of Spirit", and Mill's "On Liberty".