Yeah, the system is simple, the factors regulating all running parameters are many and their interaction pretty complex. but don't overthink it: just follow the manual and you should be basically OK. Not all engines have the same standard manual. OS and Saito have pretty good manuals, other brands might assume more base knowledge from the user, some brands even have pretty much totally rubbish manuals. Strange enough, the quality of the manual does not necessarily have any direct relation to the quality of the engines (Rossi comes to mind: their engines were the Rolls Royces among 2-strokes, but their manuals.... too small and not absorbent enough to wipe ones hiney....
).
In general, best to find a club (if you haven't allready) where they can help you hands-on. That is how I learned. The details came later.