My site is on wordpress and I need to now if there’s an easiest/quick way to make/launch the mobile version of the site.
If you need native app then you can use this ready native code for mobile http://get.wp.com/app/
If you need mobile website version then you just need to install responsive wordpress theme or install this plugin https://wordpress.org/plugins/wptouch/
You would suggest to try in your case WordPress Mobile Pack plugin, WP Mobile Detector or WPTouch.
If you’re looking for a simple mobile version of site, go for the Jetpack plugin. It’s totally free.