that helped a little.... bvut how would you start a root note? Also Just intonation is just the way of writing???

I thought there were some differences in the actual # of cycles? sorry im a dumbass...

you start a root note like you start any other note. you play it, sing it, pluck it. and no just intonation is not simply a way of writing things, it refers to the actual physics of sound and how we perceive it and it's mathematical characteristics.mostly it refers to the mathematical ratio between two notes which is perceivable by the human ear.