This is really a tough question to answer because it depends what your friend is interested in. If there’s a specific time or issue that interests them more than others then I would suggest finding something regarding that. For instance, if they like Samurai movies or Medieval knights then look for a decent, not heavy, book regarding that time frame.

You could also try something more general that covers a broad expanse of time such as Dan Carlin’s book, The End is Always Near. It’s been a while since I read that but I remember him releasing many historical events to modern day so it is more relevant and interesting.

Not a book, but you should also show them the YouTube channel called, Crash Course World History. It’s done by a history teacher in an engaging way and is meant to cover historical eras in an easy and relevant way - meant for people exactly like your friend. I would recommend starting there and then if they find a historical era or civilization they want to know more about then diving into some related books. Hope that helps!