Vue as noted in the documentation is a progressive framework for building User Interfaces. I found the best place to started was with the documentation which is very good and I am still learning and with Vue 3 due out soon out now.
The vue cli is a tool for rapid vue prototyping as it will setup a folder structure for you. It can be installed using the following command:
npm install @vue/cli -g
Firstly install the gridsome cli
npm install @gridsome/cli -g
and then to create a project
gridsome create my-gridsome-site
Unlike Vue or Gridsome you don't need to install a CLI tool for Nuxt as long as you have node installed this will work:
npx create-nuxt-app project-name