How to make 2 copies of website when updating your current site?

Hello WHT,

1.) Can I ask you how to create live copies of your website while working and updating your current site?
So when something is wrong, you can have live backup copies?

Or

2.) How to work on other hidden copies of your current site,
while testing it live
before upgrading from the non-updated version to this updated version?

I use WordPress as my CMS.

Please help,
Thank you.