The word shall is a formal word, almost like a command or declaration, such as in the case of saying, “I shall succeed,” or you could say, “you shall not be going to the dance.” It is used to imply an obligation to something. Some say that shall is used more in literature for its simple first-person future tense.
The word will, on the other hand, is a helping verb that is used with other verbs. However, it does not possess conjunction of its own. It is usually used in the second or third person for its simple future tense, such as “You will not take no for an answer,” or “They will come tomorrow.” It also implies an intension, habitual action or tendency, desire, willingness, or refusal.