The "Instruction List" section on the official SmileBASIC website teaches you how to use all the keywords.
Considering how you have prior knowledge with a programming language, you should be able to understand the basic functions of this application. But be careful; the syntax is different to that of C++, having more of an interpreted language syntax rather than a compiled language.
Fire up the way-way-back machine. This is programming the way it was before OOP. SmileBASIC does have user-defined functions with parameters and local (temporary) variables, which is a huge improvement over early BASIC. But there are no structs or classes. No local persistent state. Only global variables are persistent.
And keep in mind that this isn't the original BASIC. Just think of it as an extension to BASIC, just like C++ is an extension to C, so you'll be bound to see some new keywords here and there.
