I went the self taught route, built and rebuilt. I know you will crash. I'll put it in writing. Trees, powerlines, AND small pond. If at all possible fly from land first, with help. AMA and club membership is cheaper. Sim helps, but is not 100%. I've got a RF 4.5, still not the same. Get a blow dryer to dry electronics too!! Take the servos apart and the reciever. Been there done that, after I could fly off land. Floats are a whole different story. Turning my back to the plane as it came towards me was a help for me, as mentioned. But it doesn't work for everyone.
PLEASE TAKE VIDEOS!!! CRASHES ARE THE BEST!!!
No disrespect meant, but your in for a trip, and a surprise! No matter what ratings you have. All that you know is what the control sufaces do, and power management. PUCKER factor won't help either, you'll over control.
Again, NO Disrespect, Best of Luck,
Red