If you click on an email that has a link to a Canvas assignment...
and you are taken to a Microsoft login page...
you won't be able to sign in here (the Microsoft login is for students). Instead, you'll want to go to https://lutheransouthacademy.instructure.com/login/canvas
The parent login page will look like this:
Here, you can sign in with your personal email address (the same one that you use in Renweb) and the password that you created previously. You can use the forgot password link if you forgot your password.
Now that you're signed in to Canvas, go back to the email and you should be able to click the link and view it.