For that level, it seems lots of the kids start with some version of Garage Band. I don’t know the program at all, but I’ve seen it widely populated on Apple Devices. I think it has enough to give them an easy way to start without the pro features beginners don’t need and may even find confusing.
Cubase’s entry-level program is also an easy to use basic midi sequencer. So if there’s a MIDI lesson plan, it could certainly be used in a classroom or individual instruction setting. Cubase has its quirk about Flat Keys and Flat Notes, but by the time a student is ready to understand Keys, it won’t matter that Cubase has some peculiarities about it. Good luck.