This assumes you have Git and you've already checked out the Git repository using git clone https://github.com/cjcurrie/aso-app.git.
Install npm: https://www.npmjs.com/get-npm
In an admin-elevated shell, navigate to the project directory you cloned and run npm install. This will create a node_modules folder and install the necessary dependencies, such as Firebase and React.
To begin hosting a local developer instance, run npm run dev.
In a browser navigate to localhost:1234.
Open the browser's Developer Tools (F12 key) and check the Console to debug the project.