How to competently implement the support and editing of an existing site on wordpress?

Question

Web development

Good day. Didn't work much on wordpress. We were given a project where you need to make a lot of edits to an existing site on this engine. It is possible that changes will appear in the future.
I would like
1) the site to always work and be updated
2) there was an opportunity to show the site to the customer online before production
. I can’t figure out which way is better for this. Manipulations on hosting, git (Is it used for WordPress? Maybe you can somehow push from home, the customer to yourself and then to the server with the site) or some internal features of the engine?
Thank you.

Answer 1

Raise a copy of the server on a subdomain, make changes there and show it.
GIT can be used with any source code, including WordPress.