Hi there @TANIYAHGAVIN ,
I just wanted to add on to what @JeffCampbell mentioned.
Switching from homeroom view to classic view is a feature only available to teachers. If you are enrolled in at least one course as a student with the elementary theming enabled, Canvas will override the standard theming and will present you with the elementary theming.
Since it appears you are no longer in need of resources from your elementary school, I recommend seeing if there's a way to unenroll yourself from the course that has the elementary theming enabled. If you cannot unenroll yourself, and the course doesn't matter to you, you could try reaching out to your school's IT department so they can help you unenroll. You will then have access to the default interface that Jeff mentioned above.
However, you cannot disable the To-Do list, regardless the theme.