The ailerons are the control surfaces that are located on the trailing edge of the wing. Each moves in opposite directions when the stick is moved, resulting in the airplane rolling around the longitudinal axis. These are used to turn the airplane under most circumstances.

The newer Kadet has them and the one you have doesn't. Don't worry though because the Kadet design doesn't really need them to fly well. The rudder on the old design was used for turning the airplane and worked fine. The rudder "yaws" the airplane from side to side and on designs like the Kadet, high mounted wings with a lot of dihedral(the bend of the wings raising the tips higher than the center) which produces the turn. It isn't as smooth of a turn as one produced by ailerons but for the Kadet it works great.

In short don't bother with trying to build them since the gains aren't worth it, the Kadet flies fine on just the rudder.

FM is the way to go when buying a radio. The 4 and six channel Futaba's are reasonable and cost about $140-$210 depending on which model you decide to buy. The HiTec flash series is pretty good for the money too.