Answer 1

Most of us have C++ as our First Language but when it comes to something like Data Analysis and Machine Learning, Python becomes our go-to Language because of its simplicity and plenty of libraries of pre-written Modules.
But can C++ be used for Machine Learning too?
C++ Boost Library:- It is a powerful C++ library used for various purposes like big Maths Operations, etc.
You can refer here for installation of this Library

ML pack C++ Library:- This is a small and Scalable C++ Machine Learning Library.
You can refer here for the installation of this Library.
Note: set USE_OPENMP=OFF when installing mlpack, don’t sweat, given link has guide on how to do that

Sample CSV Data File:- As MLpack library does not have any inbuilt Sample Dataset so we have to use our own Sample Dataset.

Answer 2

DARK why do you need OOP for doing Machine Learning? The most important thing is the ability to manipulate data and store it somewhere.

Answer 3

I don't know much about Machine Learning and good C libraries for it, but here's a quora question I found that suits your needs.

https://www.quora.com/What-is-the-best-C-library-for-machine-learning