As below or any automatic procedure has been written?

1) backup your database (use phpMyAdmin to do a database export)
2) backup the wp-config.php file
3) backup the wp-content folder"

TIA

Backing up should be a frequent event. There are many plugins that will automatically backup both your database and all the other files.

But to answer your question...YES always backup before doing an upgrade, be it the theme, a plugin or even wordpress itself.
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and it's good to have a play site (a copy of your site with a differend url) to test the upgrade on before doing it to your production site.

Thank you,

And (a copy of your site with a differend url) means acquiring an new NIC name or alternately downloading WP+Atahualpa et al to my PC right?

depending on your host and the plan you have. On my plan, I can create as many subdomaind as I want, so if my domane name was juggledad.com I could create play.juggledad.com and oopsidroppedit.juggledad.com or hello.juggledad.com.

Or you could buy a new domain name. in each of these cases you would point ythe domain name to a new folder and create a new database and install a copy of your old site in it. You should go to wordpress.org and read about moving/copying your site.

Many thanks

Regards