The key philosophers I’d recommend reading about to get a kind of big picture overview of the whole of philosophy and its history would be Socrates, Aquinas, and Kant.

But it’s often better to read ABOUT them, in secondary sources, rather than trying to read those philosophers themselves. Although the Socratic dialogues are pretty easy so you may as well do those.

Branching out from there, the next key players would be Plato and Aristotle, then Descartes and Locke, then probably Hegel and Russell. Each of those pairs will give you kind of an overview of the main “sides” of philosophy in their respective eras.

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Ok great thank you. I was a little intimidated going back to the older philosophers, but I'll start browsing some of those on Amazon also.

Keep in mind that if you do want to read the original texts, a lot of the older philosophers can be read for free online, so no need to buy books of them unless you really want the paper on your shelf.

The Stanford Encyclopedia of Philosophy is also a surprisingly in-depth free online secondary source where you could learn a lot for free.

Ok thank you

Nietzsche's "On Truth and Lies in a Nonmoral Sense" and "On the Use and Abuse of History for Life" can be found online to read if they are not already included in Basic Writings and Portable Nietzsche, and are not terribly long.