It depends, if you are a beginner and want an easy to use programming language: Python is the best one to start with.
If you need optimised and advanced features (like memory management): C is more acurate
Good luck 😉
C++ as arduino and other stuff requires c++. Raspberry pi requires python. If you want both, go for python first as python is easier to learn than c++ for me. I m not sure about you but that is my recommendation