I recommend the F6...shes a stable ride, and gives plenty of warning before a stall (which WILL be nasty, indeed), She's got good dive characteristics, excellent turning, and plenty of ammo ("the whole nine yards," to be exact).
Learn the F6, and move on from there...also, learning the more difficult planes (F4U-1, P47D-11, P38) will make you much better in the long run, but for now, just stick to the basics, and join missions if possible...if you ever see me on, send me a private message, and I'll wing up with you!
Good Luck,
Gainsie