Thanks everybody for the suggestions
What I ended up doing was getting a 2018 mini over a 2012 , because the 2012 mini plus the Apple Thunderbolt adapter together was the same price as the 2018 mini
Then I connected both minis 2018 and m4 together via a Thunderbolt cable , I followed this guide
And I bought a usb kvm switch for $15 that lets me use my wired keyboard and mouse on 2 computers, with a button press
Everything is working perfectly
I’m still not sure if this was the best way or the fastest way to, but is working great so I’m happy