Build me an educational website

This website will be aimed at providing students with exemplar practice tests for a specific exam that they are preparing for. The tests will be in an online question by question format (after completing one question they move on to the next one), and at the end of each test the final screen should display their score out of a 100, and a list of all the questions they got wrong including the correct answer and explanation. I'd like for the website to be easily customisable/editable by me after it has been built by you. Also, all the questions are multiple choice, meaning that each question must have 4 answers from which the students can pick one, and at the end of the test the website should display what the student's chosen answer was and what the correct answer was. The website must have the following features: 1. Users must be able to sign up/log in. 2. After logging in they must be able to purchase the different membership options available depending on which exam they are sitting (the website will need to have multiple test packs that can be purchased). After purchasing, they must be able to have access to the tests they have purchased until a certain date set by myself, after which the membership runs out and they should no longer have access to those materials. 3. After purchasing their membership, their should be a page where there is a list of all the tests available for them to do. 4. The questions should be editable by me and I should be able to upload either images or passages or diagrams for the questions/ multiple choice answers. 5. I should be able to edit the website so that I can create more tests/options for the students to purchase, as well as add more questions in these specific tests. 6. If a user that has not yet signed in tries to purchase a test, they should be redirected to the sign up/log in page and after that redirected to the purchasing page. 7. The website will have a home page, a "list of all exam materials available" page, and an "about" page for non-logged in users. For logged in users, there should be a "Home page", "List of all exam materials available" page and a "my account page" which lists which purchases they have made and when. 8. There should be a forgot password feature for users that forget their password. This is a brief overview, if you would like more details or pictures of some sort to show what I have in mind, please get in touch! And if there are any difficulties or specific features which you cannot do, please contact me anyway and we might be able to work something out.