I really wanna create a game but don’t know how, can someone tell me?
The Wiki Tutorial: http://choicescriptdev.wikia.com/wiki/A_Basic_Tutorial
Lglasser’s Tutorial: ChoiceScript Full Tutorial (finished!)
Who is The Trenchcoat
Well, there are several places to start.
Read up on the Choice of Games outline document to get an idea of what makes a good game (you don’t need to do everything it says, that’s for Choice of Games, not Hosted Games). There are lots of good topics here on the forum about writing so you can search those, and to learn the coding parts of it, you can read up on the official site: Introduction to ChoiceScript and learn from the ChoiceScriptDev wiki.
And if you run into a problem and need help with something in particular, just post it here, lots of really helpful people here. (Do search the forum first, though, chances are your questions will already have been answered.)
Is there a way to do it on phone
Well, there are text editor apps you can install on your phone, and you can sync the files through the cloud.
You could also write on your phone on an app like Evernote and copy-paste and code it later on your computer.