https://unity3d.com/get-unity/download

• Open Unity Hub
• Go the Unity Download Archive and install version 2021.2.8 via the Unity Hub link

• If you don't know git very well, the best way to clone this project is to use https://desktop.github.com/ -- the website will have instructions for setting up github and cloning this repository.
• To open the project, you will need to have the git CLI installed

From the Unity Hub | Projects tab, click "Open," navigate to where Git checked out the project, and select the GGJ2022Project directory

There are several people in the Discord that can help you if you get stuck!