Unit Testing (Laravel 5) - Identifying test senarios

I'm new to unity testing and having a hard time identifying the correct scenarios to test.

Mainly I have following functions in my website:

View Pages

1. Retrieve values from the DB using a model

2. Pass that data into the HTML template via the controller

3. Print data in HTML template to display

//view

public function getStudents(){

$students = Student::all(); // model: get all the students from Database
$data['students'] = $students;   
return view('views/students', $data);// Pass data into the view   

}

Edit/Create Pages

1. Retrieve input data from the view file

2. Validate

3. Save/Update DB and print success message.

   public function editStudent($id){

   //grab input data
   
   //validate
   
   //save in DB
   
   

   }

Above scenario looks pretty straight forward. As long as I get database entries I get the output. Do we need to write unit tests for this? What are the test scenarios?

via Chebli Mohamed