find the mistake
 

you don't have to come if you don't want to .

ارجو ابداء الاراء

you wouldn't have to come if you don't want to

الجملة صحيحية

nothing is wrong englishboy

you won't have to come if you don't want to

الجملة صحيحة
ويمكن استخدام
won"t have to
فكلاهما صحيح
المصدر
English tenses in use 2004

You won't have to come if you don't want to

You needn't come if you don't want to
والأرجح الثانيه لآنها اختيار

you needn't come if you don't want to

needn't is the same as don't have to ,I guess he wants to use if type one so the answer is won't have to come if you don't want to

you don't have to come if you don't want to .