I am super new to WordPress and I am helping a friend to update her website. I wanted to know if there is a way to duplicate the website, which I can work on and keep the website live. I want to do this because a lot of work needs to happen on the website. I might have to change the entire template. Or if anyone has another idea, please let me know. Thanks in advance.
Yes, literally the building blocks of development. Funny you realized by your own.
You need to “clone” or “migrate” your site to a local installation (my personal preference).
Use a plugin to create a backup of your site. Duplicator and All In One Migrate are good ones.
I use a tool called LocalWP, it will install you a clean WordPress site on your PC. Then you need to restore the backup of your original site using the same plugin.
This is called Development and Production Environments
**[LocalWP](https://localwp.com/)** or **[WP Staging](https://wordpress.org/plugins/wp-staging/)**.
Both free versions would do just fine for you.