Hi Ashley -
A simple place to start would be to double-check that your device and your Canvas Student app is up to date. Sometimes, small changes in both (or either) can cause issues.
If you're good to go there, clear the cache on the next launch or uninstall and reinstall the app.
If you've done both of those things, please reply. The Community will do its best to get you up and running again.
In the meantime, check out the mobile browser version of Canvas. There have been some pretty great updates recently, and I think that it'll help you a lot as you try to access course information from your phone...and while you're trying to get the Student app to cooperate. 
This discussion post is outdated and has been archived. Please use the Community question forums and official documentation for the most current and accurate information.