Cannot GET / (mind the /) at the end, means that you have no server listening at the route / which is the path that your request “waiting for”.
If you put url/hello it will tell you Cannot GET /hello, because there isn’t either a server at that route.
So at the moment, what you have in the server.js is a piece of code that will run but not returning anything to the user (apart from that default express message), or even has a route defined.
I don’t know what exercise is this but you will likely need some app.get('/', (req,res) => { /* do stuff */ } )
Thanks for the info but I still cannot understand what you mean in your last sentence. Maybe after I finish the tutorial part that explain
how to get this app.get(‘/’, (req,res) => { /* do stuff */ } ) and why I need it, only then I understand what you mean.