education course website

My project is a website where customers take a long course (2 to 5 years to conclude) of math, english or portuguese. Each of these courses is compound of hundreds or thousands of self-learning ~20 question modules. Each module of questions has its own level. In each of these modules the student see solved examples, and works out by himself several exercises based on that example. The student works out the exercises on the browser, in my website. He reads the questions (for example: "3x55=?") and select the unswer for the question on the browser, on a dropdown list. After submit all the unswer, the system correct it and give him a grade. Next to each question there is a button that, once clicked, opens a pop up with a 1 minute video explaining how to do that exercise (in case he don't get it by the solved example). Some questions has a button to play an audio (for the pronounciation for the english and portuguese courses). Each module has about 10 to 20 questions, and the student can see only one question at a time (he can see the next question only after he submits the unswer to the previous question). The solved example of that module is always visible on the bottom of the page. After he submits all the unswers, the student sees his grade and, if he doesn't achieve 100% of accuracy, he has the option to retake the hole module, or retake just the questions he got wrong. If the student logs out, he have to take the hole module of his level (he can't retake only the wrong questions anymore once the logged out). Every module has a time couting clock, that starts when the students clicks to begin the module and stops and he submits the last question. Every time the student takes more than X minutes to conclude the module (each module has his own maximum time, chosed by me), he have to retake the hole module. The student, after log in, can only see the module avaiable for his level. Not the previous modules (that he already got) nor the future ones. Each student has a level that increases every time he got 100% of correct unswers on the previous level. The starting level of each student is diferent, and is estimated by the leveling test he takes when he sign up. The client will be charged monthly, by credit card. The client only can see and take the exercises of his current module if his payment is ok (similar to Netflix). The client pays for each subscription (math course and english course) separately. The client has an avatar that changes with his level. For example: level 1-50 has an owl, level 51-100 is an elephant, level 101-150 has a dog, etc. In case the client takes more than one course (math and english, for example), the avatar is set by his higher level. There is a maximum amount of modules a student can take each week, chosed by me. After the project is done, What I want to be customisable by myself, at any point in time, without any help from the freelancer: -All the questions, options on the dropdown list on each question, and correct unswers of each question. -The maximum amount of minutes the student has to conclude each module (this number is diferent for each module) -The solved example of each module -the avatar images, and the level range of each avatar (for example, I could change the Owl from level 1-50 to 1-60 and the elephant from 51-100 to 61-100) The student can see his grade bulletin, that includes the grade of each one of the modules he already took, and the amount of minutes he took to conclude it. The development of the hole site, including the design, is part of this project! I already have the domain. None of the tools or features that I described above is already made by me. So the developer will have to create every single one of them in this project! I hope I made myself clear. I'm avaiable to unswer any questions and I apreciate the time you spent reading this project!