can anyone explain simply how to use this thing?

[skyzzyrd]

So I read the faq and the jargon is a little technical for me. I don't even know what mounting an SD card means. ..
I have a Samsung Galaxy s6 btw if that matters.
So I downloaded a game from some site, and the file ended with something with a 7, not a zip. I couldn't find it when I looked in the emulator. Where can I find the game files so I can unzip them? And then, how do i unzip them?
Please, no jargon or abbreviations. Assume I know nothing about any of this and very little about computing and how smartphones work, because that is exactly the case.

[odditude]

you'll need to use a decompression utility like ZArchiver to extract the ROM files from the archives you downloaded.