You may read in some books that shall is used instead of will when the subject is I or we. Only a small minority of native speakers use shall other than in questions, and then only for certainty and instant decision, never for volition or habitual characteristic. Shall is used commonly in questions:
e) making a suggestion: Shall we go to the pub this evening?
f) asking if the person addressed wants the speaker to do something: Shall I arrange the publicity?