Administrator do's and don'ts

From MoodleDocs

Use a special course for imported backup files for new courses

Don't use the files area in the main Moodle site course to restore course archives. You can destroy the front page very easily. You will be much better off to set up a special course just for that purpose!

Accidentally restoring a faulty course archive to your main site course will break the whole site for everyone. Also -- by default, all users have access to the files in the main site course. If your course archive contains any confidential information, you're potentially exposing it to all site users.
Do create a hidden course to host the course archives your going to restore. Put your backups from other sites in that hidden courses files. Then restore the course from that backup.

Do use a non production site for testing

Many consider a localhost to be a beautiful thing. You can break it and not worry about impacting your production site. For example, not sure about how a plugin is going to work? Download your production code files into a localhost, change the moodle config.php file and find out.

See also