Welcome to the party!
To edit the game files and start scripting: gamefolder\web\mygame\scenes
You should find text files that you can edit in there.
To run your game: gamefolder\web\index.html or gamefolder\web\mygame\index.html
To run an automatic test of your game: gamefolder\quicktest.html or gamefolder\randomtest.html
An invaluable tool is the choicescript wiki: http://choicescriptdev.wikia.com/wiki/A_Basic_Tutorial
You might also be interested in CSIDE, a program that really streamlines writing, coding and testing games, as well as provide useful information and help: [CSIDE] The ChoiceScript IDE (v1.3.0 Now Available — 18/06/2019)
I hope you do super well! We’ll always be here for questions!