A backup is only valuable if it is separate from the device that can fail and if you know how to restore it.
You should have at least one recent backup that is physically or logically separate from the Raspberry Pi and a written restore procedure.
Step-by-step
Identify what must be backed up
For WordPress, preserve the database and wp-content at minimum. For a complete server rebuild, also preserve CloudPanel-specific configuration notes, certificate material, DNS information, and a list of installed sites.
Create a database dump
Use CloudPanel backup features or a database dump appropriate to the database engine. Store credentials securely and avoid putting passwords in shell history.
Copy site files
Back up the site user directory or at least the WordPress content directory and any custom configuration files.
Move a copy off the Pi
Send backups to another computer, NAS, encrypted cloud storage, or a separate external disk. A second folder on the same NVMe is not protection against drive failure.
Keep more than one generation
Retain multiple restore points so a bad update or unnoticed compromise does not overwrite your only clean backup.
Practice a restore
Periodically restore a copy into a test location. A successful restore is the proof that the backup process works.
You should have at least one recent backup that is physically or logically separate from the Raspberry Pi and a written restore procedure.
Troubleshooting
If a command or screen differs from the lesson, stop and verify the version you are using before forcing a change.
What you learned
You now understand the purpose of this part of the system and have a concrete result you can verify before continuing to the next lesson.