5 Answers
+ 6
With "start" you are implying that you want to learn both of them. I would say go for c++ first. Learning python after c++ will be easier than switching from python to c++.
+ 6
I've never really liked OOP in Python. Go for C++.
+ 5
In terms of the concepts/understanding I think it's easier to start with python, but since you know C already it might be worthwhile to use C++ instead and I agree with @Alex that it is easier to go from c++ to python compared with the other way round.
I program in C++/C and python and my impression is that I arrive at the implementation of a program much faster with python than with C++. python is written much more close to how we think. But then when it comes to how fast your code is, C++ outruns python. So if you have a project in mind already you can consider this.
+ 1
Go for CPP!