If you're just getting started, consider something from Horizon Hobby. With AS3X in most of the planes they carry, you'll have better luck with your learning curve. The Mustang isn't a good first plane, especially if it doesn't have a gyro.
My first plane was a UMX P-51 with AS3X. It lasted about 3 days before I destroyed it. After that, I got a trainer. Fast forward to 4 years later, I have over 30 planes. I have a few EDF jets and can fly 3D aerobatics. I still go back to a glider for some relaxing flight after flying a jet.
If you have never flown a plane but can run a rc car, you should get a trainer plane.