Each school can individually set which content can be viewed by students or parents.
If you want all students or parents to be able to see entries, first activate the "View class register" authorization for the corresponding user role in the admin area.
If only individual users should be able to see entries, you can activate the authorization in the person's profile via the user administration.
You can then adjust this authorization further in the admin area under "Visibilities & rights".
The standard settings for students and parents that they receive with the "View class register" authorization are as follows: