You can choose how to start and shut down the virtual machine using Startup and Shutdown settings.
To access Startup and Shutdown settings:
Do one of the following:
Click the Parallels Desktop icon in the menu bar and choose Configure.
If the Parallels Desktop menu bar is visible at the top of the screen, choose Actions > Configure.
Click Options and select Startup and Shutdown.
Set to Start and Shut Down the Virtual Machine Manually
If you want to always start and shut down the virtual machine manually, select Start up and shut down manually.
Configure the Virtual Machine to Start Automatically
If you want to make the virtual machine start automatically when the Mac starts, select Always ready in the background.
Specify More Details on How to Start and Shut Down the Virtual Machine Automatically
If you want to specify not only how the virtual machine starts or shuts down but also the view mode and what happens on closing the virtual machine window, select Custom and do the following:
Set Whether Windows Starts Automatically
Choose one of the following from the Start Automatically menu:
From the On Window Close menu, choose Suspend, Shut Down, Force to stop, Keep running in the background, or Ask me what to do.
Pause Windows When No Applications are Open
Select Pause Windows after and specify a period of inactivity, after which Windows will be automatically paused. Pausing Windows when there are no open applications allows you to save your Mac's CPU resources.