If you want to create back of your WordPress blog site, you need to create a copy of all the files and dump file of the database as well.
For creating the copy of files, there are two methods - accessing the WordPress root directory via an FTP client or via the File Manager in cPanel.
Here, we'll do through File Manager.
First, go to the cPanel, accessible through yourdomain.com/cpanel.
Then, go to the File Manager, located under the Files
It is important to know that if you've installed your WordPress website directly under your domain, its root folder would be public_html. But if resides under a sub-folder, it would be like public_html/subfolder.
Now you need to create a copy of the folder for data backup of the website. This can be done through the File Manager.
For downloading the files on your computer, now you'll need to create an archive of the newly created folder. After creating the archive you can download the files.
You also require creating backup of your database. For this, you can find the exact name of the database under the wp-config,php file placed in the root folder of your application. You can find the row like this:
define('DB_NAME', 'username_wp618')
To export the dump file of the database, you need to go to: cPanel>phpMyAdmin placed in the Databases section.
Thereafter, select the database which is associated to your WordPress blog website. Then click on the Export.
To export all the tables of the database, click Quick and then click on Go.
That's it. You have successfully completed the backup of your WordPress website.