Each mod is it's own separate 'series' if you will. The 'cup' folder is one series (the default one). Any mod that you add (CTS [trucks], GNS [Grand National], Nationwide, Bullring, Cup10s...whatever) will be it's own individual folder. Just place the entire mods' folder in the 'series' folder. Anything in the 'cup' folder is related solely to the 'cup' mod. Seriously, clam down and take your time.
And what, exactly, is 'Is it the same for Racin Grafix?' supposed to mean?