>>12316705Start w the greeks
Start with Plato's Gorgias. If you agree with him read his Theatetus and his Republic. After Plato read Aristotle's Nichomachaen Ethics. If you agree with him read his Rhetoric. Whether you agree or disagree, read his Metaphysics after. You don't have to read it all but it's a great step to understanding ways to perceive Metaphysics, or systems that map reality (like Physics, the modern subject instead of Aristotle's book, is a system that maps material causation).
After that, check two metaphysical heavyweights out in Parmenides and Heraclitus. From reading Plato and Aristotle you'll see how a Metaphysics can have a wide range of applications in fields like math, a creation narrative, how things exist, ethics etc. Parmenides and Heraclitus are metaphysical extremists but they come from a time before wide applications were expected. What they bring up can be answered by your metaphysics, which you already have before reading these writers.
After that I would recommend reading a nice history of philosophy that is a bit more biased towards your metaphysics so you can see their interpretation across other philosophers.
Alternatively you can read The Cave and the Light by Arthur Hermann for an even take on how universal their metaphysics is.
After that pick where you want to explore and refine your metaphysics. The next big metaphysical clash is between the Stoics and Epicureans. The largest clash would be the German Idealists where a lot of work was done trying to refute the rationalists and empiricists. Ultimately choose what draws you and after exploring that I would read another history of philosophy to tie it all together and fill in knowledge gaps then explore modern philosophy in either the Analytic or Continental philosophers to get more modern tools and terminology to put into your metaphysics.
