There are three steps to set up the development environment.
Step: 1
Install Node.js and npm from the following link
https://nodejs.org/en/download/
Verify your Node.js version. It should be Node.js version 8.x or greater and npm version 5.x or greater. Run the following command to check it.
node -v
npm -v
Install the Angular CLI globally. Run the following command.
npm install -g @angular/cli
Step: 2
Create a new project
Open a terminal or cmd. Create a new project by running the following command.
ng new new-app
Step: 3
Serve the application
Now go into the project directory and run the server. Run the following command.
cd new-app
ng serve –open
ng serve command run the server and –open option will automatically open the browser on http://localhost:4200/