Sorry about this. I'm a total noob. So here's question one - Does a Mac Mini require a charge? If it does, please disregard my "charging" comment.
So here's my setup right now:
Keyboard and mouse are connected to Raspberry Pi via USB, I would plug that into the Mac Mini
Raspberry Pi is connected to Screen with HDMI cord, I would unplug that and plug it in with one side on the Mac Mini and one side on the Screen
Raspberry Pi is powered by battery, I would unplug that to save power (Would I need to connect it to the Mac Mini? The charger is a Mini USB and I don't think it would work)
Thank you so much!