PHPStorm + Git + ISPManager = What is the best way to set up the above on a single server?

Question

git

At the moment, development is carried out in this way:
There are jobs for programmers: in the office, at home, somewhere else. PHPStorm is on these jobs.
There is a remote server that hosts both clients and the site of the development team. It has XDebug (configured), Git (not configured), ISPmanager (configured, the clients and the developers' site, in particular, have different accounts, respectively, all this is in different folders, under different users, etc.).
A project appears, work begins on it. The work takes place in such a way that a subdomain is created on the site of the development team, which acts as a test one, and work on creating a project is started on it - deploying cms there, or writing something of your own, and so on.
This is done because projects will not always have their own domain, which must be paid for and selected before that, or the domain exists, but is not served on this server, and of course, because a separate test server is needed, and separately worker.
In parallel with this, for the client, if this is required, some kind of account is created in ISPManager (well, that is, in fact, in linux), he gets some of his own goodies. There, in the future, his project will live in its working version.
In the test version, there are some edits, and so on and so forth. Sometimes they need to be rolled back only on the test version, sometimes they need to be left in it until better times, and sometimes they need to be rolled back to the working version of the project. But not always, of course, and it is hardly necessary to make some kind of backup of the working version of the project by Git, if this is done - the backups live elsewhere.
Here's what I want:
To understand if there are better options for creating test servers and testing them on the Web - and you need it in it, because they need to be shown to the client as well.
What is the best way to set up Git, where to store the test repository of the project and where is the main one, and why not use one repository with branches instead?
Is it possible and necessary to use one project in PHStorm, which will initially deploy everything to the test version, and then how to transfer everything from it to the working version? You can keep two projects in it, but then everything grows and it's not ok.

Answer 1

There is a lot of superfluous in your question, for example PHPStorm and ISPManager, we throw it away and get the question:
"How to deploy a php application from git" We search
here or in Google and find a bunch of questions and answers to them and even a sea of ​​information about the DEV environment.
As a result, you will understand that all solutions come down to the same "git pull" command, and the difference is only in how it is executed - manually or automatically.
Production and Dev do not need separate repositories, different branches and "git merge" at the right time.
And yes, you did not understand how GIT works at all, judging by "and how then to transfer everything from it to the working version?"

Answer 2

Understand if there are better options for creating test servers and testing them on the Web - and you need it on it, because they need to be shown to the client as well.

Each developer should have both a local copy of the repository and their own test server.
So that each developer does not set up his own test server, virtual machines are used with instructions (automated) for installing the project.
To send a working version of the project to the server, it is first created in git, and then deploy tools are used (for example, capistrano)