2012 Mac Mini(please help)

I got a base 2012 mac mini that I'm trying to keep in the family. I got a flash drive that I put opencore/VENTURA on but when I try to load it in the mini, it says I need at least the os x 10.10 update. My mini is stuck on 10.9.5 and CANNOT update it past that so I can't use OCLP.

What can I do to use OCLP and get this mini usable? I'm sorry if it's asked a lot but I'm very new to this.