First of all make sure you have Node installed on your computer. You can get it from here https://nodejs.org/en/download/
then you can try doing node -v in the terminal to see if it installed correctly
Now get the files from github using git clone or download.
cd into the SD-Assignment1 folder
Run npm install to download all the dependencies locally. You should get a folder created called node_modules. It contains all the info needed for all the dependencies to run and there is alot of files inside it. For this reason it is excluded from the github repo or else the repo size would be much larger.
If you ever add any dependencies/packages make sure you run npm install package_name --save from the root directory and it will automatically add it to the package.json file.
Run node app.js you should see "App listening on port 3000". After that you can test the website by typing localhost:3000 into a web browser and you should see the home page of the app. If all that works then the app is configured properly on your computer.