Depending on what you want to do on what O/S, batteries may or may not be included. I use Moonlight on a Mac to control a Windows 10 PC running Sunshine--lower latency than Remote Desktop (which I don't have anyway in the Home edition), and nicer looking than Parsec.

When you connect a patch cable directly (no crossover cable needed in the 21st century), you'll likely find that each system has a self-assigned IP in the 169.254 network.