How do you start to play the game?
This application is not available for free which means that you have to purchase it. Luckily, there is a page at GreenManGaming where all these steps are explained with pictures included as well. Basically you have to install the program and the support client then it needs to be activated. Once it has been activated, simply double click the shortcut ton your desktop and the game will start automatically.
GreenManGaming instructions: https://greenmangaming.zendesk.com/hc/en-us/articles/215465548-High-School-Dreams-How-to-Install-and-Play