While you are at it, go back and order the Tower Trainer 40. It will be a lot more forgiving and make learning more enjoyable. Just slap the engine and radio equipment in the trainer, then when you feel comfortable with it, move them over to the decathlon.

The controls on trainers are the same as everything else. The main differences are that the trainer will try and right itself more than other models, and usually flies slower than the rest. BUT it is a whole lot faster than your electrics. Basically what that means that in a turn you may hav to keep bumping the ailerons to keep it banking and you don't need to level it after a turn.

Set the radio up correctly. Ailerons and elevator on the right stick. The reason it has been done this way is that if you sit in the cockpit of a fullscale aircraft, this is how you control it, except for the foot pedals. That way if anyone was to fly your airplane, or you were to try someone elses, it will be right. Ailerons are not as bad as you think.

As far as how to adjust a Glow engine, there are several threads on that. I don't remember anyone ever pinching the fuel line on a car or truck to see if they are running lean, diesel or gasoline.