I recommend reading the official e-manual for starters. It should teach you the basics of programming, and give you examples on coding and such. You can find it here...
http://smilebasic.com/en/e-manual/10.php
Direct let you use command in real time while edit let you write the program and run all the sentence in the order that you write them.
I suggest you to read about good practices about game programming... learn the concept of game loop. Also, try to use def name instead of gosub @label