Here is what you can do.
Open a casing of a desktop PC. You will find a PSU. That PSU is called SMPS. Now go to a store and find that PSU. Grab it(of course after buying) and come home.
Short the green line with black and power the SMPS. Find the 5 volt line with 5V-15A power and split that line into many USB type-C cable.
Buy a 5 volt 15 A power source