Ouch

If you are able to OEM unlock, you probably can flash a ROM of your choosing. Now find a rom that is compatible with your device.

As other have said, calyx, or lineage are good options. but if there are unofficial they are likely to have security vulnerabilities. If thats not a deal breaker for you than try it out.

Ps make sure you have a usb 2.0 or newer. a cheap usb 1.0 will not work.

Get adb and fastboot.

Let me know how it goes!