Thanks for posting in the Community!
I understand that you are wondering about the Canvas app freezing when being sent Tasks for your enrolled Courses.
If you are seeing the app freezing, you could try clearing the app cache if you are using an iOS device. Here is a reference for that if needed: https://community.canvaslms.com/t5/Canvas-Student-iOS-Guide/What-Student-app-options-can-I-manage-fr...
Here is a video guide for using the Canvas Student app: https://community.canvaslms.com/t5/Video-Guide/Canvas-Student-App/ta-p/384213
From that guide:
To view course assignments, tap the Assignments link. The Assignments page displays all assignments in your course. To view information about an assignment, tap the name.
Also, here is the guide for using the Canvas Mobile apps for Students: https://community.canvaslms.com/t5/Student-Guide/How-can-I-use-Canvas-on-my-mobile-device-as-a-stude...
Here are all of the Canvas Student Mobile guides for iOS and Android:
Hope this helps and thanks for posting in the Community!