Making My Own Schedule For The First Time

I am realizing that I have yet to make and stick to my own schedule and routine which is a big reason why I have been feeling lost and purposeless as well as failing many many classes. Is there a good way to start making my own schedule? I want to build around class and practice time, somehow incorporate a job, specified time for homework, and a reward system for doing the things I need to do. There's so much I'm not sure how to go about this.