Steegle.One Intranet for Google Workspace
For new Google Sites see these instructions: to copy a site see Copy Site - new Google Sites; to change its URL see Sharing and Publishing - new Google Sites
Sign in to your site and use the More button (looks like a cog or a gear) and then Manage site.
Go to the General page and scroll down and use the Copy this Site button
Enter the site name, your new URL, choose if you want to keep the revisions and sharing, enter the captcha code and use the Copy site button.
This will not redirect your previous site's URL to your new site: you will need to put a link on your old site to your new site to direct visitors to the right place.
This video is best watched in high definition and in full-screen: to do this make sure you have clicked the HD button next to the time line below the video and use the Full-screen button to the right of that.