I'll give a short right now and elaborate later when you have questions. I do need a better idea of the level of the students (and you) and the goals of the project. I am guessing you want a kit that you modify to fly FPV
First I'll start on the type of aircraft you should build, then I'll mention some things I think students (and you) need to know about the physics of flying, and then I'll talk about electronics. If I have time before I got to bed, that is.
If nobody in the group has flown before, I second the recommendation of the EasyStar. I regret not using an EasyStar fuselage on one of my UAV projects. The configuration is ideal if you anticipate rough landings, which you should. It is the single most used FPV platform in the world for a reason. The fuselage can easily carry a 5800mAh 11.1V battery, camera, transmitter, etc. Everything about it, aside from lack of ailerons, suites the FPV hobby scene very well. The rear prop behind the nose and above the tail is perfect for rough landings. Three channels are enough for people who haven't flown much, especially if you're not looking to do anything more than beginner FPV. Don't worry about not having ailerons, just make sure you do tests early in the morning when the wind is calmest.
You do not want to do ailerons at that age level. Plane and simple. Turn right, Turn left, point up, point down, speed up, slow down is plenty.
I do not recommend a Balsa plane. They take a very long time to build, require a high degree craftsmanship, and can't take a crash like a good foam plane can.
On to the physics of flying:
If you don't know the basics of flight, you (and your students) need to start with longitudinal static stability
. You don't need to know all of the math, but knowing that the tail normally applies downforce, that a plane traveling too slowly will dive and that one traveling too fast will climb (and why!) is important. You might also want to hit home the importance that the plane does this. If it doesn't it will crash much faster than the pilot can correct. If you need help here, let me know.
After that I would stick to the basics of aerodynamics and flight. Smooth surfaces, smaller total area, blunt noses, sharp trailing edges, curves instead of harsh angles, etc.
My engineering background tells me that planes need to be low drag slippery pieces of high performance, but really they need to stay in the air first. Emphasis stability and control before speed and tricks and things.
For electronics you'll need to make sure you don't get any interference between transmission and your bands of receiving. You will need video and, depending on project goals, aircraft telemetry (heading, speed, battery status, etc.). I can get more into this if you want, but I would need to know more about what equipment is available.
I deleted a lot of my post when I re-read your 5th grade level comment. Good for you! You will need to be extra cautious in your safety procedures. Make dead certain everything is in top notch flying condition before committing anything to the air. Even a plane as pedestrian as an EasyStar can do some major damage. You (and your students) might want have a go at a flight sim, too.