What Do I Gain By Learning A Lot Of Languages Such As C,C++,Python and So On..?

Answer 1

flexibility, versatility and adaptability as a programmer.

Answer 2

head aches... lots of them

Answer 3

Rather than learning many similar languages, it would be valuable to learn different programming paradigms (imperative, OOP, declarative...), so you will acquire the basics to easily learn almost every programming language