Reading LLPSI, I made a list of the proper nouns with macrons in the first lesson of the first chapter:
We encounter with Italia and Eurōpa. But why Europa has a macron but Italia does not? Or why is Dānuvius but not Tiberis? I know some people recommend to just skip macrons for easyness but if I am going to learn Latin, I want to learn it properly since I'm a complete beginner.