I don't think Java's take on OOP is good to learn before you really understand OOP already. Its heavy handed style of OOP really hasn't aged that well and is rightfully being avoided in all newer languages.
I couldn't agree more. I don't know how to explain it exactly, but I had the opposite experience. Learning basics of functional programming in Python improved my OOP in Java over time.
I think it's probably more like this: learning a second, contrasting topic really helps explore the motivations that drive their respective goals.
OOP and Functional are broad classes of contrasting design patterns and philosophies but share the common idea: be principled about state.
