In production, you should install a web server like Nginx or Apache and configure it to run Symfony. This method can also be used if you're not using the Symfony local web server for development.
However for local development, the most convenient way of running Symfony is by using the local web server provided by the symfony binary. This local server provides among other things support for HTTP/2, concurrent requests, TLS/SSL and automatic generation of security certificates.
Open your console terminal, move into your new project directory and start the local web server as follows:
cd my-project/
symfony server:start
Open your browser and navigate to http://localhost:8000/. If everything is working, you'll see a welcome page. Later, when you are finished working, stop the server by pressing Ctrl+C from your terminal.