Welcome, to start with the installation first you must access the official vex essentials discord, for this, you must access the Vex Updates channel, as shown in the following image
In this channel you will find the notes of the latest update, as well as the download links of the latest version, these should look like this, download the one that best suits you :D
I highly recommend buying the premium version first
-ZuryTitan
Tip, if linkvertise blocks your download, use a different browser to download the behavior or resource depending on your case.
There is no need to explain the download, just skip the advertisement and that's it, BEWARE! the download page is always drive, in the case of the free version...
you should have two files like these, you should open them in a normal way, remember that they should have the extension (.mcpack) so that they can be executed in minecraft correctly.
if you have already successfully imported the packages you will have to apply them to your world, I recommend that you activate all the experiments even though vex only requires the use of the API BETA module.
Once you have applied and created the world you must apply the command "/reload" inside the world, if it is local, if it is inside a server (any host), you must execute the command reload from the console.
Click the image for more examples to reload