Installing software on a MacBook I'm switching from PC to a MacBook and wondered the best convention for installing new software.

For example, I've downloaded the Atom IDE, unzipped the 4 files and put into the /Users/userName/Applications Directory (which was empty, but seemed like a good place).

I then added the /Users/userName/Applications/Atom directory to the \etc\paths file, but when I type 'atom' from the bash prompt, it is not recognized.

How should I be installing software, is there a convention on where it goes?

Do I need to update the \etc\paths file or is there a location where exe's are picked up by the command line?
Generally application (.app) bundles are meant to be stored in /Applications of ~/Applications. I recommend using /Applications for the vast majority of installations, since the apps there will be accessible to other users' accounts`.

Application bundles aren't directly executable. Instead, their executable file is stored within the bundle (right click and select "Show package contents"), in {APPLICATION.app}/Contents/MacOS/

To open an Application bundle from the terminal, you can use the wicked open command with the -a flag, like: open -a /Applications/Application.app. This comes in handy occasionally, though I don't know why you'd want to open applications through terminal, rather than through the dock, dock stack, or spotlight.