How to run composer.json?

how to properly run the composer.json to create a project?

You must download composer:

curl -sS https://getcomposer.org/installer | php
 
or

php -r "readfile('https://getcomposer.org/installer');" | php
 
and next you should run if you have composer.json file:

php composer.phar install
 
or if you want create new project

php composer.phar create-project