I don't know my country's history. What can I do about it?

Hello, I am 23 years old, I'm from Greece and I m currently in university.I don't know my country's history and I feel really embarrassed about it. My friends often have conversations about stuff that happened in the past, and they all have their own opinions, but I usually remain silent, without knowing what to say. They all know history since they were kids, from school, but I was one of those kids that just didn't study these subjects much, and only paid attention to maths, physics etc. What can I do about it? How do I get started? There's seriously a lot I need to learn about my country's history and I don't know what to do.