You have to go to school.
Can I make the negative of this sentence? like this
You don't have to go to school. or
You have not to go to school.
I'm not sure which negative is meant though: There is no requirement to go to school (although you may) or You must not go.
If it's the first, you have great answers.
I'm not a teacher, but I write for a living. Please don't ask me about 2nd conditionals, but I'm a safe bet for what reads well in (American) English.