First thing's first ... you need to try to get the files that you want off the hard drive.
To do so you could use a bootable USB of Windows and a little bit of minor trickery as seen in the following linked video (I.e., backup the data to an external hard drive without booting into the oboard Windows installation on the hard drive):
View: https/youtu.be/LwK4Zkp0AQM
If you have deep underlying issues you may not be able to do so blindly without a working monitor, so to test if this is a monitor issue of the laptop display only, attach the laptop to an external display (E.g., TV) via HDMI ... if there is no display on either the computer or TV then ...
... the alternative is to remove the drive from the machine and directly connect it to an appropriate spare connector on another PC or place it in an external USB connectable enclosure (again connected to a working PC's USB port) which will allow you to access the files and back them up if the hard drive is not the issue and it is not corrupted so much as to not allow you to do so.
If neither of the monitors work then it could be time to seek out an authorised repair center or scrap the machine and get a new one (IF CHEAPER OPTION) AFTER trying a clean install of Windows to rule out corrupt Windows software installation or (more than likely Graphics driver issue) rather than a hardware issue.