I've pulled a github repository containing code for a reactjs app into one of my directories but I can't find a way to run the app on my computer. I can start a new app using create-react-app but I can't/(don't know how to) use the existing app for instead ofa freshly created one.
I'm running Ubuntu 16.04.3 on a virtual machine, my node version is 4.2.6. 
I've tried sudo apt-get install --only-upgrade nodejs but it simply says my node version is already up to date. (I include this because npm start gives me a bunch of errors and tells me that it may be because I might have to update node) but the app I create with create-react-app works fine?
The error:
 Package.json:
Package.json:
{
    "name": "my-app",
    "version": "0.1.0",
    "private": true,
    "dependencies": {
        "bootstrap": "^3.3.7",
        "express": "^4.16.2",
        "package.json": "^2.0.1",
        "prop-types": "^15.6.0",
        "react": "^16.0.0",
        "react-bootstrap": "^0.31.5",
        "react-dom": "^16.0.0",
        "react-router-dom": "^4.2.2",
        "react-scripts": "1.0.14",
        "uuid": "^3.1.0",
        "webpack": "^3.8.1"
        },
    "scripts": {
        "start": "react-scripts start",
        "build": "react-scripts build",
        "test": "react-scripts test --env=jsdom",
        "eject": "react-scripts eject"
        },
    "devDependencies": {
        "babel-cli": "^6.26.0",
        "babel-preset-env": "^1.6.1"
        }
}
 
     
     
    