How do I create a question bank website?

Hi there wapplers,

I would like to create a question bank website similar to passmedicine.com and quesmed.com. A student would pay $x to access the bank of questions per year. The questions would be around one subject and would be categorised by the topics within for students to pick and choose which topics to study.

Each question will involve: the question, a textbox for students to type their answer, a button to submit, then a mark scheme will appear for the student to tick the marks they got right, then a mark button to work out how many marks they received (for example 2/5). Once the student has marked the question, a small text will appear below the question to explain the answer/s to that question

The students overall and topic scores would be tracked.

Does anyone have any guidance on how to build something like this? Would anyone be open to helping me build it (paid of course)?

Thank you in advance
Desklamp

I have done stuff like this many times in the past as head of computer based training.
Can you clarify, the student marks his/ her own work from a marking guide rather than some sort of ai algorithm doing it (which takes the idea to another level)

Yes the student would mark their own work from a marking guide which will appear after they press submit. The AI algorithm has crossed my mind as a cool feature to develop in the future, but not in the present

Do you have any examples of the ones you have made in the past?