Hey ST,
I'd recommend studying the manuals that ship with the game to understand how the flight models work in the "game world". Google is your friend for "real world" information. Then, to marry the two worlds together (to your individual taste), you need to unpack and modify the "flight model" file which is called "buttons", using the flight model editor which is called "NTRK Wizard"... you'll be starting to appreciate that the game developers didn't really want you poking around in here!
I don't know of a FM tutorial as such--it's very much a Dark Art--and you have to remember FM "improvements" are very subjective, you're taking a complex physical object in the real universe and reducing it to a very old (but much loved) piece of gaming software. FM editing was closely guarded, I suppose in part for fear of online cheating. I have myself made simple changes like adding a 'Schilling Orifice' carburetor to early Merlin engines in Spitfires and Hurricanes (NOT historical but more fun to dogfight...IMO) as a very modest example.
To get you started, I can point you here:
https://www.sas1946.com/main/index.php?topic=55371.0Beware NTRK Wizard is UNSUPPORTED... so you're on your own out there!
For FM discussions in general, also see here:
https://forum.il2sturmovik.com/forum/94-fm-discussion/Good Luck!!
KB