Can you tell us exactly which Mac OS X version the computer has installed?
Restoring your data without a Time Machine backup of that Mac and no ability to boot to recovery and no ability to login normally is a tall order.
One option is to use another Mac to install a compatible macOS on an external drive and boot the MBP from that. You could then recovery your user files from the internal drive. After which you can wipe and reinstall macOS on the internal drive, assuming it is actually still healthy.
A second option is to create a bootable usb installer and use that to reinstall the OS on the MBP, but this will wipe the internal drive and prevent recovery of whatever user data is there.
For options one and two you'll need the use of a Mac released between 2009 and 2018, capable of running macOS 10.13 High Sierra, the newest OS that your MBP can run.
➡️ macOS 10.13 High Sierra is compatible with the Macs listed here (c.2009)
To be honest, given the circumstances, I'd go with this third option:
Replace the thirteen (!) year old, obsolete MacBook Pro.
I'd pull the drive from the old Mac, put it in an external enclosure, connect that to the new Mac and recover whatever remains of my user files.
Then I'd continue on with my newer Mac, happily computing into the next ten years with supported hardware and software.