Version Control Systems( VCS ) facilitate the management of the different versions of each developed product, as well as the possible specializations made (for example, for a specific customer).
Here are 4 simple steps to implement a version control system in your company
1.- Select the type of technology according to your needs: GIT or SVN (SubVersion).
What is the difference between GIT and SVN?

While Git and SVN are both enterprise version control systems (VCS) that help with workflow and project management in coding, they have their differences.
The difference between Git and SVN version control systems is that Git is a distributed version control system, while SVN is a centralized version control system.
Git uses several repositories, including a centralized repository and server, as well as some local repositories. SVN does not have a centralized repository.
Select the provider in which your repositories will be stored, either in the cloud or in a local server of your company.
There are many providers for hosting repositories; but here are some examples:

Visual SVN Server
https://www.visualsvn.com/
VisualSVN Server allows you to easily install and manage a fully functional Subversion-like server on the Windows platform.

Bitbucket
www.bitbucket.org/
Bitbucket is a Git-based code hosting and collaboration tool, created primarily for software development teams.

GitHub
www.github.com
GitHub is a code hosting platform for version control and collaboration that allows you to work on projects and collaborate with teams from anywhere. GitHub was recently acquired by Microsoft.

GitLab
www.gitlab.com
GitLab is an open source version control and collaboration platform that allows you to work on projects and collaborate with teams from anywhere.
3.- Select the client application that will be running on your PC to perform basic software version control operations.
Examples:

Sourcetree
https://www.sourcetreeapp.com/
It is a very easy to use GUI that provides a visual representation of your repositories. Sourcetree is a client available for MAC and Windows operating systems.

TortoiseGIT
https://tortoisegit.org/
It is a client tool for GIT. It is 100% open source (free).

TortoiseSVN
https://tortoisesvn.net/
It is a client tool based on SVN implemented as a Windows shell and very easy to use as well as being very light in size.
Implement a culture of discipline in your company in the use of best practices for an efficient and agile software version control.
This is probably the hardest part: Bringing daily discipline to your work team.
A simple recipe to follow is for the development group to perform the following best practices every day:
1.- Always update your copy of the repository on your local PC. There are basic operations in SVN and GIT to perform these tasks
Document all the changes you make to your software.
3.- Check and test that your changes work correctly.
4.- Upload the changes to either the GIT or SVN server once they have been tested and you have made sure they work correctly.