To avoid a catastrophic mistake, I would prefer not to edit the registry.
Unless you are careless it is not possible to make a catastrophic mistake in this case. Since you are using Windows 10 Home modifying the value in the registry is the only way to make this change since you are unable to use the group policy editor. Any solution described in this answer requires you to be an Administrator on the machine.
After a recent Windows update, the default option in the Shut Down
Windows dialog in Windows 10 has changed on my laptop to
previously it was
How can I restore Shut down as the default?
Within Registry Editor navigate to
HKEY_CURRENT_USER\SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer\Advanced and modify the Start_PowerButtonAction value to 0x2 (i.e. 00000002) from 0x100 (i.e. 00000100). This will change the default behavior for the current user profile.
If you want to change the default behavior for all users on the machine modify the PowerButtonAction key to 0x2 (i.e. 00000002) at the following locations:
Source: How to Change Default Action of Shut Down Windows Dialog in Windows 10