Not granting permissions will make it impossible to do work that you assign your students in the software.
User permissions are housed under the Users & Teams option in the left sidebar menu when you click into your Settings. Click the name of the specific student if you'd like to edit an individual's access. In the right pane, navigate the tabs to grant and restrict permissions.
However, it may be easier to bulk edit your students' access
You can do that by clicking the checkbox you see below with a horizontal line through it, and clicking then "Edit" option
Below are screencaps of all of the permissions we recommend you grant prior to assigning work in the software: