First thing would be "Read yourself sick on BFM, ACM, the theory of fighter combat, and just learn the lingo"
You need to understand terms like "break-turn", "E-fighting", etc. otherwise you can't understand whats being told to you.
Second "don't get mad, ask your opponent what you did wrong"
Your opponent beat you for a reason. It might be something obscure like turning right in a plane with a left-spinning prop, or as simple as you were an idiot and tried to turn fight an A6M at low speed. Ask and most people will be more than glad to help you out.
Finally, "Pick a plane and make it yours"
Try 'em all out, pick the one you like the best, and focus on that for a while. Learn its strenghts and weaknesses, and how to fly it under extreme situations without going into a stall, or a spin. Why you want to do that is because when you're new, you're learning how to fly the planes almost as much as you're learning how to fight. If you stick with one plane, you'll learn how to fly it, and be able to focus more on the learning to fight.