Welcome-
I think the help files are found on the clipboard in the opening stages of game. Click the tab that says "help" & there is useeful info there. There you can find General ifo on game controls & such.
If I had to pick the 1 most important thing for successful sorties, I would have to say its SA. SA is a big thing to understand, not only is it knowing how your plane relates to the other planes around you, but knowing how the terrain under you is, how much fuel/ammo you have, your altitude & speed state, friendles Vs Con count, it can & does go much much further. Knowing & becoming completely familiar with your view keys is mandatory for survival, as is frequently looking behind you to make sure no one is diving in on you fron 10k above & blowing you to peices before you even hear the motor.
I think its helpful to have plane knowledge. IE- P51s are stable when fast & unstable when slow, whereas a spitfire is unstable at high speeds & much more stable at lower speeds. There are many planes in the game, & each have strong & weak points. Know your plane, & how to best fight it Vs your opponants.
I fly the yak in MA, it has many attributes that make it my choice for MA. Its a medium speed plane, so I fight a spitfire differently than I would a mustang. If a spit gets on my 6 I run away, If a mustang gets on my 6, I try to keep him turning till he slows down. At that time my plane will outperform his, & within 2-3 turns I collect the kill.
All of these things can be learned in offline play. I recommend sticking with the spit for a while, especially since you already have a hand at it. Go back up, get level, get speed up & fly over your base. Pick a subject- like the Vehicle Hangar= VH. start off with flying circles around it while constantly keeping it in view out your left view, just off the wing, keep yer alt & speed all consistant. sounds easy huh? After that try some rolls, loops spirals, all keeping your target in view. Then move on to flying with the offline drones learn to keep them in view whille trying to stay in a formation besdie them.
These should help, If ya have any other questions just post em.
Ill help & so will others.
Anton