I think when someone leaves home, he or she may say like this, " I am leaving" or "I am going to school" or "I am going to work" . I am wondering what phrases native speakers usually say when they leave home for work or school.
Not a native speaker here, but I used to say "I'm heading out to/for school"
According to thefreedictionary:
Definition(head out for something): to set out for something or some place; to begin a journey to something or some place