This is primarily a user-to-user support forum; other Apple users like you. There is no way to locate it while it is off or not connected to the internet. See information in If your Mac is lost or stolen - Apple Support
If your Mac is turned off or offline, you can still use Find My to request a notification when it’s located, or lock or erase it remotely. The next time your Mac is online, the actions take effect. If you remove your Mac from Find My when it's offline, your requests are canceled.
Personally I would focus on the "If you can't find your Mac" section of If your Mac is lost or stolen - Apple Support