Congratulations on passing AIB - but don't worry about reading up on the aviation side. All the flying, in fact all the training, is based on the expectation that you know less than zero at the outset.
If you get a P slot then my suggestion would be to go gliding a few times - it will give you loads of confidence, you'll learn to balance the aircraft in turns, and you'll have fun.
Otherwise just relax, but do get fit. I'd suggest a mix of running, swimming and circuit training to give you all round stamina and strength.