For all your assignments, you will use Github for your repository and Github Pages to create a live hosted submission. To get set up with that see Setting up your repository and Setting up Github Pages.
For all assignments you will also need to be able to preview your changes locally before deploying to Github Pages. For help with that, see Local Setup.
For Assignment 5 (and ONLY assignment 5) you will be using Three.js. To get set up with that, see Three.js setup.