Make sure you have installed Nodejs in your system Node js
Make sure you have installed Reactjs globally with this command:
npm install -g create-react-app
Make sure you have installed SASS(optional) pre-processor with this command:
npm install -g sass
Copy the repo and clone it or just download it as ZIP.
Now go to the root folder in this case it's 'optiphoenix.com' and run the command:
npm install
this command will download all the dependencies related to that project.
After that just run the following command to run the project:
npm run dev
this command will run your project on http://localhost:3000/