All the changes you make in the editor are saved automatically. 

However, for them to be displayed on the live site, the site has to be published. 

There're two ways to publish your site. 

Publishing a site through an editor

 1- Open the editor by clicking Edit site

2- Click Publish in the top right corner.

 3- Done! Click Open or scan the QR code to view the site in the browser.

Publishing a site through site settings 

1- Hover over to your site and click on Settings.

2- Click Publish in the top right corner.

Note: you can still edit the site after it was published.