It is difficult to clearly state the first computer language, because the machines went through a series of changes and developments. In other words, the programming language was different for every computer.
The first programming language was written in the 1840s by Ada Lovelace. She wrote down the code for assessing Bernoulli numbers with the Analytical Engine. However, her program was only theoretical, and it was never fully implemented. Although many acknowledge her genius, her code is not recognized as the first official computer language.
In the 1940s, Konrad Zuse wrote the first high-level program for an electronic computer. It was called Plankalkul, and it was not implemented until 1998. Given the length of time it took to make Zuse's program functional, the language is not considered as the first programming language.
That honor goes to FORTRAN, which was the first fully functional program for a computer. It was launched in 1957 by IBM.
I believe the computer language you are looking for in this answer is called FORTRAN. This was really the first high level programming language, invented by scientists and mathematicians in the 1950s working for International Business Machines (IBM).
FORTRAN's name comes from The IBM Mathematical Formula Translating System. A man anmed John W. Backus was credited with the original idea and proposal, though people didn't think it was practical until they really started to develop the idea as a team. The first computer to use this language was not launched until 1957.
It was also the first computer language that operated on a number of computing platforms, sort of a very primitive, early forerunner of Bill Gates' MS-DOS.