To turn well with rudder and elevator only, a plane needs dihedral.

In the USA, the most common transmitter setup is known as Mode II. Mode II always puts the primary turning and pitch controls on the right stick. With Mode II, the primary turning control, whether it is ailerons or rudder, is always on Channel 1.

For a 4-channel plane, Mode II has the controls arranged as follows.
Right stick: ailerons (ch. 1) and elevator (ch. 2)
Left stick: throttle (ch. 3) and rudder (ch. 4)

For a 3-channel plane with rudder but no ailerons, Mode II has the controls arranged as follows.
Right stick: rudder (ch. 1) and elevator (ch. 2)
Left stick: throttle (ch. 3)

OR if the plane has ailerons but no rudder:

Right stick: ailerons (ch. 1) and elevator (ch. 2)
Left stick: throttle (ch. 3)

- Jeff