Je ne vais pas
Here's how it breaks down:
* Je: I
* ne: not
* vais: go (in the future tense)
* pas: not
Examples:
* Je ne vais pas manger. (I will not eat.)
* Je ne vais pas aller au cinéma. (I will not go to the cinema.)
* Je ne vais pas le faire. (I will not do it.)
You can also use the more formal "Je n'irai pas", but "Je ne vais pas" is the most widely used and understood.