The simple future uses the modal "will" followed by the infinitive (dropping the presposition "to"). It serves to express actions which will take place at a specified time, or to signal the beginning of an action. (If, on the other hand, one wishes to describe an action which is in the process of occurring, it is the future progressive which will be used to express it.)
One sometimes find the modal "shall" in place of "will." This usage, generally reserved for the first person, is considered archaic:
Note: this usage of "shall" to indicate the future is different from the commonplace usage of "shall" to indicate desire or wishes. See modal verbs.