FWIW,

Last year I started Flying Planks after 3 years of flying Heli's. I started with a Trainer and soloed in on the first flight. The key thing is Trainers are dosile and forgiving. They will teach you the basics of Planks. After the trainer that you will out grow quickly get a Taildragger low wing plane like a Sig 4 Star. Learn how to land it real good. Use the edge as your 3rd plane and make sure you use EXPO on those flight controls. I didn't use Expo on my Heli but I find it very usful on my planes.

Here's how I have progressed. 1 year later I am enjoying my 540T Edge and tearing up the sky. My Heli skills have even gotten better. The only other thing I can say was a big help was having a Flight Sim to learn landing and take off with a Plank.

I went Trainer, to Low wing to crashing a Low wing to another low wing to a warbird, crashed war bird did more low wing and then moved to Edge. It worked for me