Guys , thanks for your help , I am now unstuck !
I have had some success and I would like to share with you what happened to give you an alternative perspective.
Some times you have to deal with people who are not that familiar, thus unable to progress stumbling upon problems that may be invisible (due to their triviality).
Things I learned in between:
1) I dont actually have to download a local copy and build blockly games on my PC !!!
Github offers this option to clone a branch of the master code online via this codespace option
I can understand how fundamental this may sound but I was not aware there is such an option , I would not have spend soooo much time trying to set a development environment locally
I started using it , launching my local visual server code installation and it works wonders
2) Using the newly acquired knowledge of the github online cloning & codespace, I followed the steps from codelabs .
The part I could not achieve was how to run it and see my actual change changes
(what I was previously asking , admittedly not with factual accuracy , how to compile and run it )
well it turns out I had to install an extension in the Visual Studio server called 'Live Server'
This allows you to fire up the browser to pull all the latest changes and see what you are changing ....
that removed my last blocker .
I am far from done and probably will hear from me on some other topic
however at least now I can spend my time on the actual code extension and not the environment
Thanks for all your help
Regards