What is the best way to interpret a Computer language quckly and use it in actual jobs?

Learning computer language is like learning Mathematics. It's all about logic and practices. Once basic understanding of any programming language is understood become easy to replicate and use other programmings as well. Also, more practice help to advance your knowledge and create challenging scripts.

do freelance work and force yourself to practice what have you learnt

To read a computer language, it'd better to understand the syntax of that language first.

I also would like to recommend Python as a starting language. It's easy to understand and widely adopted by the industry. It's a good start point. Once you can read Python code, you can expand to other languages later.

When learning python, you can begin with a "Hello World" program, then expand to grammar, loop, if/else, and other modules that python supports.

If you are familiar with Linux, maybe give it a try on bash scripting as well. It's even simpler than Python. Save the most common commands into a bash file, and that will give you an immediate feeling how programming can increase your work efficiency. Then you can use Python for more advanced or complex tasks.

Certainly the easiest computer language to learn would be python because it reads like English and is simple to understand. Also, it is used by many companies for web and software development. There have been recent upgrades to the language so the version to learn would be python3.

There are a number of Internet websites that you can learn and practice coding python3. One of my favorite is "https://www.w3schools.com/python" which is a well organized free tutorial.

There are many things that you can do with python3. The official book that teaches all of python's capabilities is 1600 pages. Like any computer language you start learning the basics then progress to intermediate, advanced and finally mastering the language.

Also, python can be written and executed on Windows, Linux and Apple computers. Python is an open source language so if python was not installed on your computer there are easy installation instructions on the Internet. Typing python3 -V and python -V in a command window will identify the version of python install or if it is not installed.