One-Time Purchase Course Website

I need a complete educational site focused on delivering online courses sold through a simple one-time purchase model. Each course will combine clear text lessons with engaging interactive quizzes, so I need a structure that lets me upload both formats easily and track learner progress... (Budget: €8 - €30 EUR, Jobs: eLearning, HTML, LearnDash, Mobile App Development, PHP, Web Development, Website Design, WordPress)