Hello. I see it's been some time since you posted your question, but I hope I can help.
When you install sdlBasic, the reference guide and the Quick help documents (html) should be included.
You can also visit sdlbasic . net , which includes an extremely useful forum.
Also the official sdlBasic home page www . sdlbasic . altervista . org / main/index . php has many demos and programs that you can use as examples. There you have the reference guide, too.
Finally, if you need more examples or larger explanations of commands, you can download QB64 (very similar to the original QBasic) and there you will find extensive help for each instruction. You will notice it will complement the reference guide very well.
Hope this helps and congratulations for using sdlbasic!