The Screw Tape Letters and the Four Loves by C.S. Lewis

You could try reading them in your own language first and then try it in English. The screw tape letters by C.S. Lewis is easier, the four loves would be more difficult. It's more important to find things that you enjoy or you're interested in than finding the perfect thing to learn vocabulary. When you really enjoy it, you get into it and then you can do it for a long time.