In 1977, the APPLE 2 computer was the first multi-usable BASIC-language computer, families could create their own game programs on the APPLE 2 and the other BASIC-language household computers of the 1980's. Beginner's All-purpose Symbolic Instruction Code.

I would start by reading the manual (tap once to smilebasic to select), reading the source from the samples and changing minor values to understand what is happening, and using the '?' button in the editor whenever you put in an argument like 'PRINT'. There's also a PDF in the website if you look.