If I call something a function does that mean I'm "doing functional programming" any time I use it?

I use both C++ and Python but I wouldn't describe any of what I write as "object oriented".

No. Functional programming is quite a bit more involved than just writing "functions"--it is taking advantage of the fact that functions are first-class "objects" that can be passed as arguments to other functions, which allows for a far more intuitive and flexible form of programming. But FP is even more than that.