My experience with Python is limited to some play code only slightly more complex than hello world, so this won't be a very in-depth answer for python specifically, but I can tell you this:
The differences between the languages is in details like the syntax and certain language specifics will be different (like the different ways errors are handled, I/O capabilities and how compilers convert your input into something executable), but C++ and Python both offer the same paradigms, so problem solving can be done in much the same way with both languages. Both C++ and Python are Imperative and Object Oriented, so you're probably going to pick up python quite fast if you're comfortable with C++ once you've mastered the new syntax using problem solving techniques you've picked up with C++. If you want to, you can use Python for functional programming as well, but I've never touched that part, so I can't tell you much about it.
Is it too early? I can't really tell from your story in a definitive yes or no.
Are you already confident enough to write full (GUI) applications with C++? (i.e. use libraries, more complex language features like generics and/or templating etc.)
I think that learning a new language paradigm is much harder than learning a new language in the same paradigm family. When you step out into new paradigm territory, you'll have to spend much more time for getting a good idea of how to solve problems with that paradigm.
Between OO languages there are differences as to how inheritance is dealt with, and how data is passed in the memory when you pass a parameter/argument to a function affecting performance. But to get going these are usually of minor concern at first.
My guess is that if you're confident enough with C++ to do something more than hello world in a fancy way, you're ok for launch.
Learning many languages superficially will help you understand code samples regardless of the language used, but creating your own code requires a bit more understanding of how the languages work and how they differ from each other.
P.S. When I want to learn how to use a new language superficially, I'll usually try the following things to get a feel for the language syntax and superficial workings:
- Hello world (Text on screen)
- Hello world written to a file (teaches you the basics on file I/O for that language, and very often other kinds of I/O as well)
- Doing some standard calculations with different bases (10, hex, octal), both integer and floating point. (teaches you about truncation and number notation)
- Try to use some graphical library to show hello world in a fancy dialog. (teaches you how to use libraries and external code)