@vince22 :The OP has a MBP 2012 , so latest supported OS is Catalina.
OpenCore as a first step might be a bit over the top IMHO...
There are reports of issues with the 870 EVO (and the QVO series) in Macs , so I would recommend e.g. a 860 EVO or a Crucial instead.
RAM can be upgraded to 2x 8GB 1600 MHz DDR3 max and runs fine, especially together with a SSD installed you'll notice a nice performance boost.
BTW: depending on the latest OS version ever installed on your MBP , i would first check the firmware version of your device and run the Catalina installer (if necessary) with the OEM disk installed to get the latest firmware . In some cases the installer refuses to update the firmware with a 3rd party disk installed.