A basic knowledge of Git is pretty much essential to a professional developer, although I think that understanding what git is and how it works is much more important than knowing the commands. I actually avoid using the command line and instead use a GUI, it allows me to visualize everything that is going on much better. If you are interested, I use Tower:
https://www.git-tower.com/mac/
Also - this is an earlier thread on this topic that has lots of helpful information - I don't understand Git and GitHub