RE: A few questions from a new guy
Buy a low-wing tail draggerto practice with until your confidence and skills are up-to-par with what's required for a P-51. I have a Pulse XT40 from Hangar 9 that's great- low wing, decent size, and flies almost like a trainer but not. My take-offs and landings are now looking pretty scale-like which is great and I have the thumb/finger skills that I'll need to get a P-51 off the ground and more importantly back on the ground in one piece. That P-51 you got is WAYnice to crash and burn within the first few minutes of your first flight. Put her in the hangar for now, and practice with a low wing taildragger tobuildup your skills and confidence.
I'm looking for a P-51 myself now and have been eye-balling the Hangar9P-51 Blue Nose for some time. Best of luck with your plane! She's a beauty!