Measure electrical consumption from electric panel
With admitted 'less than basic' knowledge about electricity, that means you must not make any connections to the mains on your board. 

What you want is a clamp-on current transformer on each wire you want to monitor. This usually takes the form of 2 C-cores, with either a winding round one of them, or Hall sensor or two embedded in them. These will isolate the  mains from your low voltage measurements. I am not going to recommend any particular part numbers, but at least you know what to search for now.

Most people doing this sort of thing would assume constant mains voltage, and unity power factor, and not measure it. It's only worth doing if you are making metering-quality measurements, which it sounds like you're not.