If you use PCs that have Ethernet cards built after 2012, you can just buy a single Ethernet cable that is produced after 2012, plug one end into PC #1, plug the other end into PC #2, and you're good to go.
Modern computers (anything made in the last 15+ years) use Auto-MDIX, meaning the network cards will automatically figure out how to talk to each other without needing an old-school "crossover" cable or a central box.
From that point on you just need to set your static IPs on each of the PCs and the connection between them will be fine.