Question: Noobie here.

Should I open Mac terminal and cd to /Applications/Blender/ which is where my Blender app is? Doesn't seem to work for me trying to run script from Text screen in Blender. I guess there is no way to see output within Blender itself?

Answer: 
A really quick way for mac users to do this is to create an alias using the Terminal (It's not as scary as it looks)

open Terminal

type `nano ~/.bash_profile`

on the first line paste this `alias blender='/Applications/blender-2.80.0/blender.app/Contents/MacOS/blender'`

Exit nano by `ctrl + x` and press `y` to save changes

type `source ~/.bash_profile`

You only need to do this once.

Now every time you need to open Blender from the command line, open terminal and type `blender`

Blender will launch from the terminal and you can see the output.
It seem's I cannot comment.

Small note, blender 3.x is located at:
`/Applications/Blender.app/Contents/MacOS/Blender`