C++ is a programming language that expanded upon the existing C language. I has all of the "old ways" of sepparating things into functions, but it also features the new Object Oriented approach which allows devs to split the source into classes (which define objects, which can contain functionality and attributes). I'm assuming it's related to AUTOMATED testing and not so much to MANUAL testing. As far as I know, automated testing involves repeatedly testing a program or a certain part of a program in some sort of loop, while manual testing involves simply playing the game and reporting / documenting bugs.
EDIT: The actual installation of the game seriously just invloves you:
RIght clicking the downloaded archive - extracting it somewhere - double clicking the .exe file inside of the folder that was just extracted.
But, the game might ask you to install redistributables, which are basicaly some packages that applications use to run I think. To do that you can simply google the name of the package given in the error message and download and install it using the instructions given on the site from which you downloaded. Just make sure you download from the OFFICIAL sources, definitely not from some site that doesn't have the secure connection lock icon next to the URL like this.
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Also you should note that since your PC doesn't have those packages in the first place, and since you're referring to your internet connection as "the internet", it's safe to assume that your computer most likely can't even handle the game, so you shouldn't bother trying anymore. No offense.