[deanhills]

The git command not found because the git package probably isnt installed
try using apt-get or yum depending on your distro to install the git package

Agreed that this is probably the problem.  @Amresh - you can Google this problem and how to load and set up git and git permissions if you haven't got the package installed yet. 

There are many tutorials online for how to install the Git package, this one is a good example of which install commands to use:

https://www.liquidweb.com/kb/install-git-ubuntu-16-04-lts/

There are plenty of tutorials for setting up git for the first time, the one below is a good example:
https://git-scm.com/book/en/v2/Getting-S...-Git-Setup