With Find My not on, there is no way to see where your device is. Apple cannot turn it on remotely, so you are left with reporting the lost device to your local police and also notifying the cellular provider to block cellular access.
If your iPhone or iPad was stolen - Apple Support
With your device using a Passcode, there is no way for anyone to access the data on your device before it would be locked due to too many failed attempts (as long as you did not use something like "1111"). Without the Activation Lock protections with Find My it would be able to be reset where your data is wiped and could be set up by anyone.
Where are you viewing your device list when you previously stated that you did not have the Apple Account Password, Trusted Device, and also seeing the message that the Apple Account was not valid. Was it the case of a mistyped Apple Account or something else?