You do NOT need to watch any of the other Fate Anime in order to enjoy the new anime Fate Grand Order Babylonia. Yes, it would be helpful, but you can watch this as a standalone series, with no knowledge on the Fate Universe whatsoever and still enjoy what you’re watching.
Now if you want to be less confused while watching this show, then join me as I go through the basics and fundamentals of the Fate Universe. As well as a little prologue into the Grand Order timeline!
Fate/Stay Night Servants Explained: https://www.youtube.com/watch?v=ENWsTmJDQhw&list=PLcX4f6aL0IajxVlEbPHc2JiVel9zbHGg0
Fate/Apocrypha Servants Explained: https://www.youtube.com/watch?v=AMu2leLY958&list=PLcX4f6aL0IagX0FoycVv4nxJcBBT2bq1a