Looks like an excellent guide, even for adults!

The fact that each subroutine has its own dedicated window really helped me to create my first complex program when I was young. Type F2 to access any routine directly. A program was a set of subroutines rather than a set of lines.

There was an online help too, and a survival guide.

You can try it out here: https://www.pcjs.org/software/pcx86/sys/dos/microsoft/5.00/ . It will launch MS-DOS 5 on a PC/AT. Type QBASIC to launch it.