Hello @ShemsiKeyhani
Thank you for contacting the Canvas Community. We're sorry to hear you've been experiencing issues with your to-do list. If you've been added as a TA to a course with your same login for classes you've taken in the past (most likely) then your to-do list will include assignments you need to grade in addition to assignments you'd submit in normal classes. This is intended behavior and you can view all by clicking the bottom of your to-do list or using the calendar. Announcements should still be coming through as normal and you can check your notification settings to make sure you're getting the proper notifications:
Here is the Canvas guide:
https://community.canvaslms.com/t5/Student-Guide/How-do-I-manage-my-Canvas-notification-settings-as-...
https://community.canvaslms.com/t5/Student-Guide/How-do-I-use-the-To-Do-list-and-sidebar-in-the-Dash...
