The easiest way to check for a new version of CMC is to navigate to your Joomla backend -> Extensions -> Extension manager -> Update. Click on find updates. If we've issues a CMC update that is compatible with your Joomla version it show up in the list.
Another way to check for the latest updates is to visit our site https://compojoom.com and go to Downloads->CMC. The latest available version is going to be on the top.