U bent hier

Prepare laptop for node/npm environment

First installed npm:
sudo apt install npm
Then installed the latest angular/CLI (sudo, because -g is global and you require /usr/local/bin-access)
sudo npm install -g @angular/cli@latest
Then go to the folder where to start a first project
cd ~/somewhere
And start a new angular project:
ng new my-first-app
Then a folder ~/somewhere/my-first-app is created containing template files for the empty project.

Now start the server-side job with:
ng server
(Make sure you are in the project folder