Get version of unity with visual effect graph and how to install it

I recommend using the latest stable version. For visual effect graph to work you, need a Scriptable Render Pipeline, short SRP. Universal Render Pipeline or High Definition Render Pipeline are prebuild SRPs.
You can install them in the package manager. Maybe take a look at this tutorial.
Then install visual effect graph also in the package manager, maybe you have to enable experimental packages. You can find a tutorial about installing visual effect graph here.

By the way, it would not be hard to google this by your own.