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.
If you want to always start and shut down the virtual machine manually, select Start up and shut down manually.
If you want to make the virtual machine start automatically when the Mac starts, select Always ready in the background.
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:
Choose one of the following from the Start Automatically menu:
Note: Windows starts when you open a Windows application, regardless of this setting.
Never: Windows never starts automatically.
When a window opens: Windows starts automatically when you open it from the Control Center.
When Parallels Desktop starts: Windows starts automatically when you start Parallels Desktop.
When the user logs in: Windows starts automatically when the macOS user logs in to macOS on the Mac startup.
This setting affects the view mode, in which Windows starts when you start the virtual machine or a guest OS application.
From the Startup View menu, choose Coherence, Window, Full Screen, Picture in Picture, Headless, or Same as last time.
Note: Headless mode is available in Parallels Desktop for Mac Pro Edition only.
Choose one of the following from the On VM Shutdown menu:
Keep the window open: If Windows is set to appear in a separate window, the window stays open when you stop or shut down Windows.
Close window: If Windows is set to appear in a separate window, the window closes when you stop or shut down Windows.
Quit Parallels Desktop: Parallels Desktop quits when you stop or shut down Windows.
These settings affect what happens only when Windows is set to appear in a separate window.
From the On Window Close menu, choose Suspend, Shut Down, Force to stop, Keep running in the background, or Ask me what to do.
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.