In the "TEACHER" environment, click on the "TESTS" tab. You can select the correct class using a drop-down menu in the top-right of the screen.
Options for individual student settings
You can see the general settings by clicking on the 'arrows down' icon under the 'settings' subtab.
And after that click on 'student settings' to change settings for individual students.
You can, for example, give individual students more time for the test or an extra allowed attempt.
When you change settings for individual students, make sure to select the students it applies to before saving.