Figured this one out - didn't realize there's an Octane Blender to start-up, not the Blender installation pre-Octane.
Once I figured out that the Octane Addon was there.

I installed the free version - the OctaneRender is activated.
When going to the list of AddOns in Blender, I do not see the OctaneRender Engine.
I do see the add in C:\ProgramFiles\BlenderOctane/2.82/scripts\addons\ - and I see all the py files - but I don't know how to install the addon.
Any advice?

Do you have the icon in the system tray?
Are you running Windows?