Install meteor from here link
Go inside the app directory and run the below command
sudo meteor npm install
This will install all the necessary packages which are also mentioned in package.json file in the root directory
Go inside the app directory and run the below command
sudo meteor update --all-packages
This will install all the meteor packages (which a little different from node modules).
In the app directory enter the command sudo meteor
and the app will build up, install all the necessary meteor packages and finally run the app at http://localhost:3000