How to design the database for a results management application?

I'm building a result management application for my college project, and I am having trouble creating an ideal database schema.

The whole course has multiple semesters, S1, S2, S3 ... until S8. Each semester has different subjects.

S1 = ['sub1','sub2','sub3','sub4','sub5','sub6'];
S2 = ['sub1','sub2','sub3','sub4','sub5','sub6'];
...
S8 = ['sub1','sub2','sub3','sub4','sub5','sub6'];

Each subject has the following fields:

sub1 = ['status','inteal_marks','exteal_marks','total_marks', 'percentage'];
sub2 = ['status','inteal_marks','exteal_marks','total_marks', 'percentage'];
...
sub6 = ['status','inteal_marks','exteal_marks','total_marks', 'percentage'];

Say there are students A, B, C ... until Z.

What I have tried:

I couldn't get an idea for designing the database, so what I have now is an array (JSON) in the following format:

$array = [
  'A' => [
    'sub1' => [
      'pass' => 'value',
      'inteal' => 'value',
      'exteal' => 'value',
      'total' => 'value',
      'percentage' => 'value',
    ],

    ...

    'sub6' => [
      'pass' => 'value',
      'inteal' => 'value',
      'exteal' => 'value',
      'total' => 'value',
      'percentage' => 'value',
    ],   
  ]

  ...

  'Z' => [
    'sub1' => [
      'pass' => 'value',
      'inteal' => 'value',
      'exteal' => 'value',
      'total' => 'value',
      'percentage' => 'value',
    ], 

    ...

    'sub6' => [
      'pass' => 'value',
      'inteal' => 'value',
      'exteal' => 'value',
      'total' => 'value',
      'percentage' => 'value',
    ],   
  ]
];

When a student enters their roll number, I want to display the semester-wise results of each student, including their percentage.

I'm sure this is a simple question for database design experts, but I'm a begier here, so please do give me some pointers on how to solve this.