Hi,
I have over 17 years experience flying RC planes, and I am rated as an examiner to test other pilots for safe flying so they can fly at public displays.
So here is my pennies worth.
High wing trainner with ailerons? No need for rudder in the turns at the stage you are at. I don't teach people to use rudder until they start aerobatics.
The comments above re the sim setup are spot on. If you can let go of the sticks and the model remains straight and level for 5 - 10 seconds then the sim is ok, if not you need to adjust the trims until it will.
Once this is set ok, the secret is, give the plane what it wants. This will be different in every turn. So, lets say you are going to turn left, roll until the wing bank is about 30 deg's, then look at the fus nose to tail. When the plane is flying level the nose and tail are level. This still stands even when the wing is banked. So, with your wing at 30 deg, look at the nose, it will drop a little, so you only need a little back pressure on the elevator to put it back to level. Too much and it will climb. Once you are almost pointing in the direction you wish to go roll the wings level, adjust the nose if neccessary. This is all easy said I know, but if you keep giving the plane what it wants this will all get smoother. I just started helis last year, my flying was all over the place. Hours spent on the sim have improved this and now my real world model heli is looking better. It will pay off.
Another benifit of the sim is in orientation. You will learn how the model looks from different angles. This is something that helps a lot at the field. You will also start to get the hang of the control neccessary when the model is comming towards you, left appears to go right, whats happening?????
This all helps you at the filed and believe it or not, real life is easier than the sim because you can tell where the ground is, not always easy on the sim.

Keep with it, then you will be hooked like the rest of us