For PHP you'll want to install two package management applications. The first is Phive. You can use this to install Composer and later PHPUnit.
The second is Composer, this is the most popular package management system for PHP, it can also generate autoload files for your project.
Once in your project directory you can run composer install to have composer execute its config.
You'll also need Node.js and npm, the popular JS package management program. This one you can install at your OS level and at the VM level. You need the former if you want to use BackstopJS to perform visual regression testing.
Enter the project directory and if the project uses composer run composer install.
If the project uses npm run npm install.