How to download a package and install in my unity project

Hello everyone,
I’m new in Unity and I am following a game developer on Youtube.
There is a script for “2D Platformer Character Controller” and a zip folder to download it.
But here comes to problem… How can I use this script in my project?

I tried to import it and nothing happens by replacing the folder in my project folder.
There is no json package. I can’t open by a new project to see what it is.

How do I have to do with a zip folder and put it in my project.
Is there another methode to do it?
Did somebody used this zip file ?

Nevermind. I found out that it’s a zip folder with assets from a learning video.
And I don’t need it because it’s with scripts. So I mean is with codes written.
And I will use Playmaker in the game.