If it were me, I would suggest, in order;
1) Read netaces.org in depth, and anything else you can find related to the mechanics of ACM.
2) Do a familiarization offline. Just get your controls sorted out, find the command keys, learn how to set and use the radio, etc...
3) Go online, and straight to the Training Arena. Hook up with an AH Trainer, and do whatever they tell you. Spend a lot of time there, at first. You could probably ask for an appointment right here on this board, and one will agree to meet you at a specific time and date.
4) Take your lessons from training, and bring your n00bie butt to the Main Arena to try things out in the soup.
5) Eat humble pie for quite some time. Finally land your first kill, get excited, then eat more pie.
6) Once you're fully in the MA, keep up your training. You'll get your backside handed to you on a platter for awhile, but you'll get better.
7) After awhile, start to evaluate squads. Don't take the first invite sombody screams over the radio "ANYBODY WANNA JOIN MY NEW SQUAD?". Check out websites, then request an opportunity to fly with a squad for a while, to get a feel for the group and the game they play. Make a careful selection, as you'll find your squad can have an influence on your game and skills, and experienced squaddies can teach you tons. Plus, you start to enjoy the interaction with bunches of people.
In a lot of ways, I think the steep learning curve is part of the appeal here. You will not pick this up in a half-hour. Years from now, you'll still be discovering how to use and react to the environment and refining your tactics. On top of that, you've got over 70 or 80 machines to master, as well.
And forget everything you know about 'flying' in WW2 or BF2. That's arcade-game flying. This is far more like the real thing, and that much tougher.
Luck!