Let's start with pitch-yaw-and roll. Elevator is pitch. Rudder is yaw. Aileron is roll. Most people in the US use mode 2 controls which put pitch and roll on the right stick and throttle and yaw on the left stick. There are other setups, but they aren't as popular in the US. A simulator is OK for basic muscle memory developement and when it is raining, but a trainer in the air is my pick for training. Although some people aren't aware of it and only use the right stick. If done properly, both sticks are used for turning. A basic trainer can get by with 4 channels, but if you are going to buy a radio anyway, more channels are better for use later. 6-7 will work for most smaller planes. It would be your pick on the airframe selection and electronics. Personally I would go with a brand name radio, but that is just me.