My degree is in philosophy, from one of the top handful of schools in that field. Learning by reading is more or less essential in philosophy, however I'm going to recommend against any of the books with a high level overview, or really any tertiary sources. Frankly, they are all either quite bad, or grinding the author's political axe (political in the sense of academic politics).

If you learn by reading, read primary sources: Protagoras, Plato, Aristotle, Descartes, Hume, Kant, Hegel (the Science of Logic in particular), in that order, are basically what you need to get caught up to modernity in philosophy. After that, you should have a strong enough background to truly engage with whatever sub topic you want.

For contemporary English speaking philosophy, the path after the above would be Frege, Russel, Wittgenstein (Tractatus then philosophical investigation), Quine, Davidson, Sellars, McDowell .

If you want to get into extremely contemporary stuff, find professors webpages at top institutions and read the PDFs of their papers they post there, they nearly all make them freely available, but they absolutely are not written for lay audiences: read the background stuff above first.

Secondary sources are also great, when done right: read the primary sources first. Eg "The 25 years of philosophy" is a great trip, but make sure you read Kant and Hegel first! (Fichte and Schelling are optional.)

Some translation are really bad... The Cambridge series is mostly modern improved translations, but do some research on each particular book first. Except Kant, just use the Kemp Smith translation.