Build a Website

I need to start an online education portal which needs to be interactive. Lessons and tutorials will appear. Navigation will be based on user input. The website will pick up data from a backend server. There will be questions and answers on the website, it will accept user's solutions and will validate them, depending on which it will show the solution, or next lesson, or the next problem. Users need to be able to create their account, and their progress needs to be monitored.