No I hadn’t spotted that command so I tried it but it still wouldn’t run. But you pointed me in the right direction, I did some searching on npm install which lead me back to some of the serverless hello world examples
I saw that I had initially installed serverless globally by running
npm install serverless -g
so I took a punt and tried
npm install serverless
in the project directory to see what would happen. This appeared to do the trick as I now have the node_modules sub directory installed below the project, I changed the launch.json program value back to the value in the accepted answer on stack overflow tried again and it debugged straight into it.
So I now have the hello world example up and running which is great, thanks for the suggestion !