Help setting up ml-agents-dodgeball-env project

ml-agents-dodgeball-env project detup issues:

Env:

 Linux Manjaro 21.1

 Unity Hub 2.4.5

 Unity Editor 2020.3.24f1 (LTS)

    ML Agents 2.1.0-exp.1
    ML Agentn Extensions 0.5.0-preview

 Successful Git installs: 

     /home/xxxxx/Desktop/Unity/ml-agents/

         /home/xxxx/Desktop/Unity/ml-agents/com.unity.ml-agents/
         /home/xxxx/Desktop/Unity/ml-agents/com.unity.ml-agents.extensions/
         /home/xxxx/Desktop/Unity/ml-agents/ml-agents-dodgeball-env/

ML_Agents Unity Projects that I have successfully set up:

  /home/xxxx/Desktop/Unity/ml-agents/com.unity.ml-agents/Project/Assets/ML-Agents/

 Examples successfully installed into project and run in inference mode - no issues.

Instructions followed for setting up ml-agents-dodgeball-env from here: (https://github.com/Unity-Technologies/ml-agents-dodgeball-env)

 "To open this repository, you will need to install the Unity editor version 2020.2.6 or later. (DONE)

 Clone the dodgeball-env branch of this repository by running: (DONE)

 git clone https://github.com/Unity-Technologies/ml-agents-dodgeball-env.git

 Open the root folder in Unity. Then, navigate to Assets/Dodgeball/Scenes/TitleScreen.unity, open it, 
 and hit the play button to play against pretrained agents. You can also build this scene (along with 
 the Elimination.unity and CaptureTheFlag.unity scenes) into a game build and play from there. "

Opening the "root" folder in Unity? Please explain what this is.. for example is it:

a) open /home/xxxx/Desktop/Unity/ml-agents/ml-agents-dodgeball-env/ as a project? - does not work, results in too many errors to document.

b) open /home/xxxx/Desktop/Unity/ml-agents/ml-agents-dodgeball-env/Assets/Dodgeball/Scenes/TitleScreen.unity as a scene? - does not work either.

I am not new to Machine Learning but I am very new to Unity. I feel quite embarrassed that I couldn't get past this seemingly simple problem. Can anyone please provide a more detailed installation guide that may be suitable for an Unity novice?

Thanks