Don't apologise, we all have to start somewhere, and the subject of industrial sewing machines can be quite complex (initially, at least). I'd still like to see a closeup of your threading around the tension assembly.
The number of holes used on the post and the bar next to the tension unit can vary, depending on how much extra "pre"-tension might be needed. It's often a trial and error thing to suit the materials being sewn, but normally you would only use two holes on the post and one or two on the bar.