I listened to Donald Kagan's lectures on Ancient Greeks. His lectures made me interested in the themes in Greek history and how it influenced the modern world. I read a few things about V D Hanson and watched a few of his speeches. I must say that I was impressed by his view of the world. But then, I read a few answers written by u/Iphikrates and am reserving judgement on VDH's views. I am from a non-western country which has a fairly democratic government but has a long way to go. I believe that I must learn about the origins of the polity that governs my country. I wish to become a proponent of Democracy and one day write about it. Where should I start? How should I study it?
You could look at this reading list which is the University of Cambridge's suggested reading for classical history that I've been using to look for books on Roman history, but there's an abundance of books on Greek history such as Athenian Democracy too.