If I want to be a hacker what languages should I learn or master in?

Answer 1

What exactly do you mean by hacker? It's commonly misunderstanding term. Also, it will be probably more about knowledge of algorithms and cryptography.

Answer 2

For whatever purpose you meant by using the word "Hacker", the more you know the better it is. You can "Hack" things when you fully understand their inner workings...
One of the best practical examples that knowledge is power.

Answer 3

Kali Linux may be useful for you

Answer 4

Python. It is ever so easy to quickly write one off scripts to do precisely what you want. Combined with the great number of open source (iow free as in beer) libraries and modules so much of the code you want to write has already been written and you merely need to string it together in a proper order. In my opinion anyway 😀