Which programming languag is necessary to learn at first .?

Answer 1

c++

Answer 2

It completely depends on what you want to do after learning the language. If your only purpose is to learn, then I would suggest you to start with something which has easier syntax. Like Python. If the language is easier to understand then the learner will find more interest in learning it.
I started with C. Luckily for me, I found interest in that. :)